From 970f87792d52b74e14641d05b4440291b674fd1b Mon Sep 17 00:00:00 2001
From: BlackMATov <blackmatov@gmail.com>
Date: Thu, 30 May 2019 14:13:08 +0700
Subject: [PATCH] utils to c++17

---
 headers/enduro2d/math/unit.hpp                |  4 +-
 headers/enduro2d/utils/_all.hpp               |  1 +
 headers/enduro2d/utils/_utils.hpp             |  2 +
 headers/enduro2d/utils/color.hpp              | 10 +--
 headers/enduro2d/utils/color32.hpp            | 10 +--
 headers/enduro2d/utils/filesystem.hpp         | 15 ++--
 headers/enduro2d/utils/filesystem.inl         |  8 +--
 headers/enduro2d/utils/image.hpp              |  4 +-
 headers/enduro2d/utils/mesh.hpp               |  4 +-
 headers/enduro2d/utils/module.hpp             |  4 +-
 headers/enduro2d/utils/path.hpp               |  4 +-
 headers/enduro2d/utils/shape.hpp              |  4 +-
 headers/enduro2d/utils/streams.hpp            | 15 ++--
 headers/enduro2d/utils/streams.inl            |  4 --
 headers/enduro2d/utils/strfmts.hpp            | 70 +++++++++----------
 headers/enduro2d/utils/strings.hpp            | 65 ++++++++---------
 headers/enduro2d/utils/strings.inl            | 42 ++++++-----
 headers/enduro2d/utils/time.hpp               | 14 ++--
 headers/enduro2d/utils/url.hpp                | 25 +------
 headers/enduro2d/utils/xml_utils.hpp          |  4 +-
 sources/enduro2d/utils/color.cpp              |  8 +--
 sources/enduro2d/utils/color32.cpp            |  8 +--
 sources/enduro2d/utils/filesystem.cpp         |  4 +-
 .../enduro2d/utils/filesystem_impl/files.hpp  |  4 +-
 .../utils/filesystem_impl/files_posix.cpp     |  4 +-
 .../utils/filesystem_impl/files_winapi.cpp    |  4 +-
 .../utils/filesystem_impl/filesystem.hpp      |  4 +-
 .../utils/filesystem_impl/filesystem_ios.mm   |  4 +-
 .../filesystem_impl/filesystem_linux.cpp      |  4 +-
 .../filesystem_impl/filesystem_macosx.mm      |  4 +-
 .../filesystem_impl/filesystem_windows.cpp    |  4 +-
 sources/enduro2d/utils/image.cpp              |  4 +-
 .../enduro2d/utils/image_impl/image_impl.hpp  |  4 +-
 .../utils/image_impl/image_reader_dds.cpp     |  4 +-
 .../utils/image_impl/image_reader_pvr.cpp     |  4 +-
 .../utils/image_impl/image_reader_stb.cpp     | 10 +--
 .../utils/image_impl/image_writer_dds.cpp     |  4 +-
 .../utils/image_impl/image_writer_pvr.cpp     |  4 +-
 .../utils/image_impl/image_writer_stb.cpp     | 10 +--
 sources/enduro2d/utils/json_utils.cpp         | 18 ++---
 sources/enduro2d/utils/mesh.cpp               |  4 +-
 .../enduro2d/utils/mesh_impl/mesh_impl.hpp    |  4 +-
 .../utils/mesh_impl/mesh_reader_e2d.cpp       |  7 +-
 sources/enduro2d/utils/path.cpp               |  4 +-
 sources/enduro2d/utils/shape.cpp              |  4 +-
 .../enduro2d/utils/shape_impl/shape_impl.hpp  |  4 +-
 .../utils/shape_impl/shape_reader_e2d.cpp     |  7 +-
 sources/enduro2d/utils/streams.cpp            |  4 +-
 sources/enduro2d/utils/strings.cpp            |  4 +-
 sources/enduro2d/utils/url.cpp                | 10 +--
 sources/enduro2d/utils/xml_utils.cpp          |  4 +-
 untests/sources/untests_core/vfs.cpp          |  4 +-
 52 files changed, 226 insertions(+), 257 deletions(-)

diff --git a/headers/enduro2d/math/unit.hpp b/headers/enduro2d/math/unit.hpp
index 4b951de3..5fa03184 100644
--- a/headers/enduro2d/math/unit.hpp
+++ b/headers/enduro2d/math/unit.hpp
@@ -226,7 +226,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace math
+namespace e2d::math
 {
     //
     // approximately
@@ -279,4 +279,4 @@ namespace e2d { namespace math
     bool contains_nan(const unit<T, Tag>& u) noexcept {
         return !math::is_finite(u.value);
     }
-}}
+}
diff --git a/headers/enduro2d/utils/_all.hpp b/headers/enduro2d/utils/_all.hpp
index baf63f6f..4c0362f4 100644
--- a/headers/enduro2d/utils/_all.hpp
+++ b/headers/enduro2d/utils/_all.hpp
@@ -23,6 +23,7 @@
 #include "path.hpp"
 #include "shape.hpp"
 #include "streams.hpp"
+#include "streams.inl"
 #include "strfmts.hpp"
 #include "strings.hpp"
 #include "strings.inl"
diff --git a/headers/enduro2d/utils/_utils.hpp b/headers/enduro2d/utils/_utils.hpp
index 401cadb1..d0d848e6 100644
--- a/headers/enduro2d/utils/_utils.hpp
+++ b/headers/enduro2d/utils/_utils.hpp
@@ -15,6 +15,8 @@ namespace e2d
     class buffer_view;
     class color;
     class color32;
+    class read_file;
+    class write_file;
     class image;
     class mesh;
     class shape;
diff --git a/headers/enduro2d/utils/color.hpp b/headers/enduro2d/utils/color.hpp
index 39dc886b..b2b1801a 100644
--- a/headers/enduro2d/utils/color.hpp
+++ b/headers/enduro2d/utils/color.hpp
@@ -38,7 +38,7 @@ namespace e2d
         const f32* data() const noexcept;
 
         f32& operator[](std::size_t index) noexcept;
-        f32  operator[](std::size_t index) const noexcept;
+        f32 operator[](std::size_t index) const noexcept;
 
         color& operator+=(f32 v) noexcept;
         color& operator-=(f32 v) noexcept;
@@ -74,7 +74,7 @@ namespace e2d
     color operator/(color l, const color& r) noexcept;
 }
 
-namespace e2d { namespace math
+namespace e2d::math
 {
     bool approximately(const color& l, const color& r) noexcept;
     bool approximately(const color& l, const color& r, f32 precision) noexcept;
@@ -88,10 +88,10 @@ namespace e2d { namespace math
     color saturated(const color& c) noexcept;
 
     bool contains_nan(const color& c) noexcept;
-}}
+}
 
-namespace e2d { namespace colors
+namespace e2d::colors
 {
     u32 pack_color(const color& c) noexcept;
     color unpack_color(u32 argb) noexcept;
-}}
+}
diff --git a/headers/enduro2d/utils/color32.hpp b/headers/enduro2d/utils/color32.hpp
index 1937e6c9..c7f9b91b 100644
--- a/headers/enduro2d/utils/color32.hpp
+++ b/headers/enduro2d/utils/color32.hpp
@@ -38,7 +38,7 @@ namespace e2d
         const u8* data() const noexcept;
 
         u8& operator[](std::size_t index) noexcept;
-        u8  operator[](std::size_t index) const noexcept;
+        u8 operator[](std::size_t index) const noexcept;
 
         color32& operator+=(u8 v) noexcept;
         color32& operator-=(u8 v) noexcept;
@@ -74,7 +74,7 @@ namespace e2d
     color32 operator/(color32 l, const color32& r) noexcept;
 }
 
-namespace e2d { namespace math
+namespace e2d::math
 {
     bool approximately(const color32& l, const color32& r) noexcept;
     bool approximately(const color32& l, const color32& r, u8 precision) noexcept;
@@ -85,10 +85,10 @@ namespace e2d { namespace math
     color32 minimized(const color32& c, const color32& cmin) noexcept;
     color32 maximized(const color32& c, const color32& cmax) noexcept;
     color32 clamped(const color32& c, const color32& cmin, const color32& cmax) noexcept;
-}}
+}
 
-namespace e2d { namespace colors
+namespace e2d::colors
 {
     u32 pack_color32(const color32& c) noexcept;
     color32 unpack_color32(u32 argb) noexcept;
-}}
+}
diff --git a/headers/enduro2d/utils/filesystem.hpp b/headers/enduro2d/utils/filesystem.hpp
index c42e1bd4..8b84dfe6 100644
--- a/headers/enduro2d/utils/filesystem.hpp
+++ b/headers/enduro2d/utils/filesystem.hpp
@@ -4,8 +4,6 @@
  * Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
  ******************************************************************************/
 
-#ifndef E2D_INCLUDE_GUARD_B13171AF5FD34D6284271BD2F4B1F6DD
-#define E2D_INCLUDE_GUARD_B13171AF5FD34D6284271BD2F4B1F6DD
 #pragma once
 
 #include "_utils.hpp"
@@ -13,17 +11,21 @@
 
 namespace e2d
 {
+    class read_file;
+    using read_file_uptr = std::unique_ptr<read_file>;
+
     class read_file : public input_stream {
     public:
         virtual const str& path() const noexcept = 0;
     };
-    using read_file_uptr = std::unique_ptr<read_file>;
+
+    class write_file;
+    using write_file_uptr = std::unique_ptr<write_file>;
 
     class write_file : public output_stream {
     public:
         virtual const str& path() const noexcept = 0;
     };
-    using write_file_uptr = std::unique_ptr<write_file>;
 }
 
 namespace e2d
@@ -32,7 +34,7 @@ namespace e2d
     write_file_uptr make_write_file(str_view path, bool append) noexcept;
 }
 
-namespace e2d { namespace filesystem
+namespace e2d::filesystem
 {
     bool remove(str_view path);
     bool exists(str_view path);
@@ -86,7 +88,6 @@ namespace e2d { namespace filesystem
     };
 
     bool extract_predef_path(str& dst, predef_path path_type);
-}}
+}
 
 #include "filesystem.inl"
-#endif
diff --git a/headers/enduro2d/utils/filesystem.inl b/headers/enduro2d/utils/filesystem.inl
index 6da5cafd..f9b72004 100644
--- a/headers/enduro2d/utils/filesystem.inl
+++ b/headers/enduro2d/utils/filesystem.inl
@@ -4,14 +4,12 @@
  * Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
  ******************************************************************************/
 
-#ifndef E2D_INCLUDE_GUARD_ADA6066FA64F4B30BE65FE6AFB3D887F
-#define E2D_INCLUDE_GUARD_ADA6066FA64F4B30BE65FE6AFB3D887F
 #pragma once
 
 #include "_utils.hpp"
 #include "filesystem.hpp"
 
-namespace e2d { namespace filesystem
+namespace e2d::filesystem
 {
     template < typename Iter >
     bool extract_directory(str_view path, Iter result_iter) {
@@ -28,6 +26,4 @@ namespace e2d { namespace filesystem
             return true;
         });
     }
-}}
-
-#endif
+}
diff --git a/headers/enduro2d/utils/image.hpp b/headers/enduro2d/utils/image.hpp
index 9a06bbb5..877bdaa8 100644
--- a/headers/enduro2d/utils/image.hpp
+++ b/headers/enduro2d/utils/image.hpp
@@ -93,7 +93,7 @@ namespace e2d
     bool operator!=(const image& l, const image& r) noexcept;
 }
 
-namespace e2d { namespace images
+namespace e2d::images
 {
     bool try_load_image(
         image& dst,
@@ -112,4 +112,4 @@ namespace e2d { namespace images
         const image& src,
         image_file_format format,
         const output_stream_uptr& dst) noexcept;
-}}
+}
diff --git a/headers/enduro2d/utils/mesh.hpp b/headers/enduro2d/utils/mesh.hpp
index d2be19d2..7aaa7dda 100644
--- a/headers/enduro2d/utils/mesh.hpp
+++ b/headers/enduro2d/utils/mesh.hpp
@@ -97,7 +97,7 @@ namespace e2d
     bool operator!=(const mesh& l, const mesh& r) noexcept;
 }
 
-namespace e2d { namespace meshes
+namespace e2d::meshes
 {
     bool try_load_mesh(
         mesh& dst,
@@ -106,4 +106,4 @@ namespace e2d { namespace meshes
     bool try_load_mesh(
         mesh& dst,
         const input_stream_uptr& src) noexcept;
-}}
+}
diff --git a/headers/enduro2d/utils/module.hpp b/headers/enduro2d/utils/module.hpp
index aa0b6ca0..75aa3772 100644
--- a/headers/enduro2d/utils/module.hpp
+++ b/headers/enduro2d/utils/module.hpp
@@ -72,7 +72,7 @@ namespace e2d
     std::unique_ptr<BaseT> module<BaseT>::instance_;
 }
 
-namespace e2d { namespace modules
+namespace e2d::modules
 {
     template < typename ImplT, typename... Args >
     ImplT& initialize(Args&&... args) {
@@ -97,4 +97,4 @@ namespace e2d { namespace modules
         using BaseT = typename ImplT::base_type;
         return static_cast<ImplT&>(module<BaseT>::instance());
     }
-}}
+}
diff --git a/headers/enduro2d/utils/path.hpp b/headers/enduro2d/utils/path.hpp
index 7314fa99..00f2ef78 100644
--- a/headers/enduro2d/utils/path.hpp
+++ b/headers/enduro2d/utils/path.hpp
@@ -8,7 +8,7 @@
 
 #include "_utils.hpp"
 
-namespace e2d { namespace path
+namespace e2d::path
 {
     str combine(str_view lhs, str_view rhs);
 
@@ -25,4 +25,4 @@ namespace e2d { namespace path
 
     bool is_absolute(str_view path) noexcept;
     bool is_relative(str_view path) noexcept;
-}}
+}
diff --git a/headers/enduro2d/utils/shape.hpp b/headers/enduro2d/utils/shape.hpp
index 909d3d5a..859a5aa6 100644
--- a/headers/enduro2d/utils/shape.hpp
+++ b/headers/enduro2d/utils/shape.hpp
@@ -77,7 +77,7 @@ namespace e2d
     bool operator!=(const shape& l, const shape& r) noexcept;
 }
 
-namespace e2d { namespace shapes
+namespace e2d::shapes
 {
     bool try_load_shape(
         shape& dst,
@@ -86,4 +86,4 @@ namespace e2d { namespace shapes
     bool try_load_shape(
         shape& dst,
         const input_stream_uptr& src) noexcept;
-}}
+}
diff --git a/headers/enduro2d/utils/streams.hpp b/headers/enduro2d/utils/streams.hpp
index 63369117..dc0775a8 100644
--- a/headers/enduro2d/utils/streams.hpp
+++ b/headers/enduro2d/utils/streams.hpp
@@ -4,8 +4,6 @@
  * Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
  ******************************************************************************/
 
-#ifndef E2D_INCLUDE_GUARD_271E0872955E4A59980866CBF737BDC1
-#define E2D_INCLUDE_GUARD_271E0872955E4A59980866CBF737BDC1
 #pragma once
 
 #include "_utils.hpp"
@@ -19,6 +17,9 @@ namespace e2d
         }
     };
 
+    class input_stream;
+    using input_stream_uptr = std::unique_ptr<input_stream>;
+
     class input_stream : private noncopyable {
     public:
         virtual ~input_stream() noexcept = default;
@@ -27,7 +28,9 @@ namespace e2d
         virtual std::size_t tell() const = 0;
         virtual std::size_t length() const noexcept = 0;
     };
-    using input_stream_uptr = std::unique_ptr<input_stream>;
+
+    class output_stream;
+    using output_stream_uptr = std::unique_ptr<output_stream>;
 
     class output_stream : private noncopyable {
     public:
@@ -37,7 +40,6 @@ namespace e2d
         virtual std::size_t tell() const = 0;
         virtual void flush() const = 0;
     };
-    using output_stream_uptr = std::unique_ptr<output_stream>;
 }
 
 namespace e2d
@@ -99,7 +101,7 @@ namespace e2d
     input_stream_uptr make_memory_stream(buffer data) noexcept;
 }
 
-namespace e2d { namespace streams
+namespace e2d::streams
 {
     bool try_read_tail(
         str& dst,
@@ -116,7 +118,6 @@ namespace e2d { namespace streams
     bool try_write_tail(
         const buffer& src,
         const output_stream_uptr& stream) noexcept;
-}}
+}
 
 #include "streams.inl"
-#endif
diff --git a/headers/enduro2d/utils/streams.inl b/headers/enduro2d/utils/streams.inl
index 7cd6dce7..f26500bb 100644
--- a/headers/enduro2d/utils/streams.inl
+++ b/headers/enduro2d/utils/streams.inl
@@ -4,8 +4,6 @@
  * Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
  ******************************************************************************/
 
-#ifndef E2D_INCLUDE_GUARD_8B0A2CAB69114FA69A716D2CC7F64DD4
-#define E2D_INCLUDE_GUARD_8B0A2CAB69114FA69A716D2CC7F64DD4
 #pragma once
 
 #include "_utils.hpp"
@@ -41,5 +39,3 @@ namespace e2d
             : *this;
     }
 }
-
-#endif
diff --git a/headers/enduro2d/utils/strfmts.hpp b/headers/enduro2d/utils/strfmts.hpp
index cf79c8c8..d185bf02 100644
--- a/headers/enduro2d/utils/strfmts.hpp
+++ b/headers/enduro2d/utils/strfmts.hpp
@@ -13,14 +13,14 @@
 #include "color32.hpp"
 #include "strings.hpp"
 
-namespace e2d { namespace strings
+namespace e2d::strings
 {
     //
     // vec2
     //
 
     template < typename T >
-    class format_arg<vec2<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<vec2<T>, std::enable_if_t<std::is_integral_v<T>>> {
         vec2<T> value_;
         u8 width_;
     public:
@@ -37,7 +37,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<vec2<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<vec2<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         vec2<T> value_;
         u8 width_;
         u8 precision_;
@@ -59,7 +59,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<vec3<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<vec3<T>, std::enable_if_t<std::is_integral_v<T>>> {
         vec3<T> value_;
         u8 width_;
     public:
@@ -77,7 +77,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<vec3<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<vec3<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         vec3<T> value_;
         u8 width_;
         u8 precision_;
@@ -100,7 +100,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<vec4<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<vec4<T>, std::enable_if_t<std::is_integral_v<T>>> {
         vec4<T> value_;
         u8 width_;
     public:
@@ -119,7 +119,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<vec4<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<vec4<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         vec4<T> value_;
         u8 width_;
         u8 precision_;
@@ -143,7 +143,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<quat<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<quat<T>, std::enable_if_t<std::is_integral_v<T>>> {
         quat<T> value_;
         u8 width_;
     public:
@@ -162,7 +162,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<quat<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<quat<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         quat<T> value_;
         u8 width_;
         u8 precision_;
@@ -186,7 +186,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<rect<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<rect<T>, std::enable_if_t<std::is_integral_v<T>>> {
         rect<T> value_;
         u8 width_;
     public:
@@ -205,7 +205,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<rect<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<rect<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         rect<T> value_;
         u8 width_;
         u8 precision_;
@@ -229,7 +229,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<aabb<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<aabb<T>, std::enable_if_t<std::is_integral_v<T>>> {
         aabb<T> value_;
         u8 width_;
     public:
@@ -250,7 +250,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<aabb<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<aabb<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         aabb<T> value_;
         u8 width_;
         u8 precision_;
@@ -276,7 +276,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<mat2<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<mat2<T>, std::enable_if_t<std::is_integral_v<T>>> {
         mat2<T> value_;
         u8 width_;
     public:
@@ -293,7 +293,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<mat2<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<mat2<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         mat2<T> value_;
         u8 width_;
         u8 precision_;
@@ -315,7 +315,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<mat3<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<mat3<T>, std::enable_if_t<std::is_integral_v<T>>> {
         mat3<T> value_;
         u8 width_;
     public:
@@ -333,7 +333,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<mat3<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<mat3<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         mat3<T> value_;
         u8 width_;
         u8 precision_;
@@ -356,7 +356,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<mat4<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<mat4<T>, std::enable_if_t<std::is_integral_v<T>>> {
         mat4<T> value_;
         u8 width_;
     public:
@@ -375,7 +375,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<mat4<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<mat4<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         mat4<T> value_;
         u8 width_;
         u8 precision_;
@@ -399,7 +399,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<rad<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<rad<T>, std::enable_if_t<std::is_integral_v<T>>> {
         rad<T> value_;
         u8 width_;
     public:
@@ -415,7 +415,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<rad<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<rad<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         rad<T> value_;
         u8 width_;
         u8 precision_;
@@ -436,7 +436,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<deg<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<deg<T>, std::enable_if_t<std::is_integral_v<T>>> {
         deg<T> value_;
         u8 width_;
     public:
@@ -452,7 +452,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<deg<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<deg<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         deg<T> value_;
         u8 width_;
         u8 precision_;
@@ -478,7 +478,7 @@ namespace e2d { namespace strings
     public:
         template < typename U >
         explicit format_arg(U&& value)
-            noexcept(noexcept(std::is_nothrow_constructible<url, U>::value))
+            noexcept(noexcept(std::is_nothrow_constructible_v<url, U>))
         : value_(std::forward<U>(value)) {}
 
         std::ptrdiff_t write(char* dst, size_t size) const {
@@ -499,7 +499,7 @@ namespace e2d { namespace strings
     public:
         template < typename U >
         explicit format_arg(U&& value, u8 width = 0)
-            noexcept(noexcept(std::is_nothrow_constructible<str, U>::value))
+            noexcept(noexcept(std::is_nothrow_constructible_v<str, U>))
         : value_(std::forward<U>(value)), width_(width) {}
 
         std::ptrdiff_t write(char* dst, size_t size) const {
@@ -527,7 +527,7 @@ namespace e2d { namespace strings
     public:
         template < typename U >
         explicit format_arg(U&& value, u8 width = 0)
-            noexcept(noexcept(std::is_nothrow_constructible<wstr, U>::value))
+            noexcept(noexcept(std::is_nothrow_constructible_v<wstr, U>))
         : value_(std::forward<U>(value)), width_(width) {}
 
         std::ptrdiff_t write(char* dst, size_t size) const {
@@ -555,7 +555,7 @@ namespace e2d { namespace strings
     public:
         template < typename U >
         explicit format_arg(U&& value, u8 width = 0)
-            noexcept(noexcept(std::is_nothrow_constructible<str16, U>::value))
+            noexcept(noexcept(std::is_nothrow_constructible_v<str16, U>))
         : value_(std::forward<U>(value)), width_(width) {}
 
         std::ptrdiff_t write(char* dst, size_t size) const {
@@ -583,7 +583,7 @@ namespace e2d { namespace strings
     public:
         template < typename U >
         explicit format_arg(U&& value, u8 width = 0)
-            noexcept(noexcept(std::is_nothrow_constructible<str32, U>::value))
+            noexcept(noexcept(std::is_nothrow_constructible_v<str32, U>))
         : value_(std::forward<U>(value)), width_(width) {}
 
         std::ptrdiff_t write(char* dst, size_t size) const {
@@ -652,7 +652,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<seconds<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<seconds<T>, std::enable_if_t<std::is_integral_v<T>>> {
         seconds<T> value_;
         u8 width_;
     public:
@@ -668,7 +668,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<seconds<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<seconds<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         seconds<T> value_;
         u8 width_;
         u8 precision_;
@@ -689,7 +689,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<milliseconds<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<milliseconds<T>, std::enable_if_t<std::is_integral_v<T>>> {
         milliseconds<T> value_;
         u8 width_;
     public:
@@ -705,7 +705,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<milliseconds<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<milliseconds<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         milliseconds<T> value_;
         u8 width_;
         u8 precision_;
@@ -726,7 +726,7 @@ namespace e2d { namespace strings
     //
 
     template < typename T >
-    class format_arg<microseconds<T>, std::enable_if_t<std::is_integral<T>::value>> {
+    class format_arg<microseconds<T>, std::enable_if_t<std::is_integral_v<T>>> {
         microseconds<T> value_;
         u8 width_;
     public:
@@ -742,7 +742,7 @@ namespace e2d { namespace strings
     };
 
     template < typename T >
-    class format_arg<microseconds<T>, std::enable_if_t<std::is_floating_point<T>::value>> {
+    class format_arg<microseconds<T>, std::enable_if_t<std::is_floating_point_v<T>>> {
         microseconds<T> value_;
         u8 width_;
         u8 precision_;
@@ -757,4 +757,4 @@ namespace e2d { namespace strings
                     make_format_arg(value_.value, width_, precision_)));
         }
     };
-}}
+}
diff --git a/headers/enduro2d/utils/strings.hpp b/headers/enduro2d/utils/strings.hpp
index 084e8516..ce195c36 100644
--- a/headers/enduro2d/utils/strings.hpp
+++ b/headers/enduro2d/utils/strings.hpp
@@ -4,8 +4,6 @@
  * Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
  ******************************************************************************/
 
-#ifndef E2D_INCLUDE_GUARD_4540A3A22AD942D8A6B0C77A3346E73A
-#define E2D_INCLUDE_GUARD_4540A3A22AD942D8A6B0C77A3346E73A
 #pragma once
 
 #include "_utils.hpp"
@@ -15,8 +13,8 @@ namespace e2d
     template < typename Char >
     class basic_string_hash final {
     public:
-        basic_string_hash() noexcept;
-        ~basic_string_hash() noexcept;
+        basic_string_hash() noexcept = default;
+        ~basic_string_hash() noexcept = default;
 
         basic_string_hash(basic_string_hash&& other) noexcept;
         basic_string_hash& operator=(basic_string_hash&& other) noexcept;
@@ -84,45 +82,44 @@ namespace e2d
     wstr_hash make_hash(wstr_view src) noexcept;
     str16_hash make_hash(str16_view src) noexcept;
     str32_hash make_hash(str32_view src) noexcept;
+}
 
-    namespace strings
-    {
-        class format_error;
-        class bad_format;
-        class bad_format_buffer;
-        class bad_format_argument;
+namespace e2d::strings
+{
+    class format_error;
+    class bad_format;
+    class bad_format_buffer;
+    class bad_format_argument;
 
-        template < typename T, typename = void >
-        class format_arg;
+    template < typename T, typename = void >
+    class format_arg;
 
-        template < typename T, typename... Args >
-        format_arg<std::decay_t<T>> make_format_arg(T&& v, Args&&... args);
+    template < typename T, typename... Args >
+    format_arg<std::decay_t<T>> make_format_arg(T&& v, Args&&... args);
 
-        template < typename... Args >
-        std::size_t format(
-            char* dst, std::size_t size,
-            str_view fmt, Args&&... args);
+    template < typename... Args >
+    std::size_t format(
+        char* dst, std::size_t size,
+        str_view fmt, Args&&... args);
 
-        template < typename... Args >
-        bool format_nothrow(
-            char* dst, std::size_t dst_size, std::size_t* length,
-            str_view fmt, Args&&... args) noexcept;
+    template < typename... Args >
+    bool format_nothrow(
+        char* dst, std::size_t dst_size, std::size_t* length,
+        str_view fmt, Args&&... args) noexcept;
 
-        template < typename... Args >
-        str rformat(
-            str_view fmt, Args&&... args);
+    template < typename... Args >
+    str rformat(
+        str_view fmt, Args&&... args);
 
-        template < typename... Args >
-        bool rformat_nothrow(
-            str& dst,
-            str_view fmt, Args&&... args) noexcept;
+    template < typename... Args >
+    bool rformat_nothrow(
+        str& dst,
+        str_view fmt, Args&&... args) noexcept;
 
-        bool wildcard_match(str_view string, str_view pattern);
+    bool wildcard_match(str_view string, str_view pattern);
 
-        bool starts_with(str_view input, str_view test) noexcept;
-        bool ends_with(str_view input, str_view test) noexcept;
-    }
+    bool starts_with(str_view input, str_view test) noexcept;
+    bool ends_with(str_view input, str_view test) noexcept;
 }
 
 #include "strings.inl"
-#endif
diff --git a/headers/enduro2d/utils/strings.inl b/headers/enduro2d/utils/strings.inl
index 99749a3c..12c97fc2 100644
--- a/headers/enduro2d/utils/strings.inl
+++ b/headers/enduro2d/utils/strings.inl
@@ -4,8 +4,6 @@
  * Copyright (C) 2018-2019, by Matvey Cherevko (blackmatov@gmail.com)
  ******************************************************************************/
 
-#ifndef E2D_INCLUDE_GUARD_5BC5A803A3694674845E9953209E8CBE
-#define E2D_INCLUDE_GUARD_5BC5A803A3694674845E9953209E8CBE
 #pragma once
 
 #include "_utils.hpp"
@@ -13,12 +11,6 @@
 
 namespace e2d
 {
-    template < typename Char >
-    basic_string_hash<Char>::basic_string_hash() noexcept = default;
-
-    template < typename Char >
-    basic_string_hash<Char>::~basic_string_hash() noexcept = default;
-
     template < typename Char >
     basic_string_hash<Char>::basic_string_hash(
         basic_string_hash&& other) noexcept
@@ -189,7 +181,7 @@ namespace std
     };
 }
 
-namespace e2d { namespace strings
+namespace e2d::strings
 {
     //
     // exceptions
@@ -268,7 +260,7 @@ namespace e2d { namespace strings
 
     template < typename T >
     class format_arg<T, std::enable_if_t<
-        std::is_integral<T>::value && std::is_signed<T>::value>>
+        std::is_integral_v<T> && std::is_signed_v<T>>>
     {
         T value_;
         u8 width_;
@@ -292,7 +284,7 @@ namespace e2d { namespace strings
 
     template < typename T >
     class format_arg<T, std::enable_if_t<
-        std::is_integral<T>::value && std::is_unsigned<T>::value>>
+        std::is_integral_v<T> && std::is_unsigned_v<T>>>
     {
         T value_;
         u8 width_;
@@ -316,7 +308,7 @@ namespace e2d { namespace strings
 
     template < typename T >
     class format_arg<T, std::enable_if_t<
-        std::is_floating_point<T>::value>>
+        std::is_floating_point_v<T>>>
     {
         T value_;
         u8 width_;
@@ -404,20 +396,28 @@ namespace e2d { namespace strings
     namespace impl
     {
         template < typename T >
-        struct is_arg_impl : std::false_type {};
-        template < typename U >
-        struct is_arg_impl<format_arg<U>> : std::true_type {};
-        template < typename T >
-        struct is_arg : is_arg_impl<std::remove_cv_t<T>> {};
+        struct is_arg_impl
+        : std::false_type {};
 
         template < typename T >
-        std::enable_if_t<is_arg<std::decay_t<T>>::value, T>
+        struct is_arg_impl<format_arg<T>>
+        : std::true_type {};
+
+        template < typename T >
+        struct is_arg
+        : is_arg_impl<std::remove_cv_t<T>> {};
+
+        template < typename T >
+        inline constexpr bool is_arg_v = is_arg<T>::value;
+
+        template < typename T >
+        std::enable_if_t<is_arg_v<std::decay_t<T>>, T>
         wrap_arg(T&& arg) {
             return std::forward<T>(arg);
         }
 
         template < typename T >
-        std::enable_if_t<!is_arg<std::decay_t<T>>::value, format_arg<std::decay_t<T>>>
+        std::enable_if_t<!is_arg_v<std::decay_t<T>>, format_arg<std::decay_t<T>>>
         wrap_arg(T&& value) {
             return make_format_arg(std::forward<T>(value));
         }
@@ -602,6 +602,4 @@ namespace e2d { namespace strings
             return false;
         }
     }
-}}
-
-#endif
+}
diff --git a/headers/enduro2d/utils/time.hpp b/headers/enduro2d/utils/time.hpp
index 7ca8ee04..70b41cc7 100644
--- a/headers/enduro2d/utils/time.hpp
+++ b/headers/enduro2d/utils/time.hpp
@@ -86,7 +86,7 @@ namespace e2d
     };
 }
 
-namespace e2d { namespace time
+namespace e2d::time
 {
     template < typename T >
     std::chrono::duration<T, std::ratio<1ll, 1ll>>
@@ -120,9 +120,9 @@ namespace e2d { namespace time
     microseconds<T> to_microseconds(const unit<T, Tag>& u) noexcept {
         return u.template convert_to<microseconds_tag>();
     }
-}}
+}
 
-namespace e2d { namespace time
+namespace e2d::time
 {
     template < typename T >
     const seconds<T>& second() noexcept {
@@ -177,9 +177,9 @@ namespace e2d { namespace time
         static microseconds<T> hour_us = to_microseconds(hour<T>());
         return hour_us;
     }
-}}
+}
 
-namespace e2d { namespace time
+namespace e2d::time
 {
     template < typename TimeTag, typename T = i64 >
     unit<T, TimeTag> now() noexcept {
@@ -196,7 +196,7 @@ namespace e2d { namespace time
     }
 
     template < typename T = i64 >
-    inline unit<T, milliseconds_tag> now_ms() noexcept {
+    unit<T, milliseconds_tag> now_ms() noexcept {
         return now<milliseconds_tag, T>();
     }
 
@@ -204,4 +204,4 @@ namespace e2d { namespace time
     unit<T, microseconds_tag> now_us() noexcept {
         return now<microseconds_tag, T>();
     }
-}}
+}
diff --git a/headers/enduro2d/utils/url.hpp b/headers/enduro2d/utils/url.hpp
index aa048d39..457f6427 100644
--- a/headers/enduro2d/utils/url.hpp
+++ b/headers/enduro2d/utils/url.hpp
@@ -21,19 +21,13 @@ namespace e2d
         url& operator=(const url& other);
 
         explicit url(str_view schemepath);
-        url(str_view scheme, str_view path) noexcept;
-
-        template < typename T, typename U >
-        url(T&& scheme, U&& path) noexcept;
+        url(str scheme, str path) noexcept;
 
         url& assign(url&& other) noexcept;
         url& assign(const url& other);
 
         url& assign(str_view schemepath);
-        url& assign(str_view scheme, str_view path) noexcept;
-
-        template < typename T, typename U >
-        url& assign(T&& scheme, U&& path) noexcept;
+        url& assign(str scheme, str path) noexcept;
 
         url& concat(str_view path);
         url& append(str_view path);
@@ -53,21 +47,6 @@ namespace e2d
     };
 }
 
-namespace e2d
-{
-    template < typename T, typename U >
-    url::url(T&& scheme, U&& path) noexcept {
-        assign(std::forward<T>(scheme), std::forward<U>(path));
-    }
-
-    template < typename T, typename U >
-    url& url::assign(T&& scheme, U&& path) noexcept {
-        scheme_ = std::forward<T>(scheme);
-        path_ = std::forward<U>(path);
-        return *this;
-    }
-}
-
 namespace e2d
 {
     void swap(url& l, url& r) noexcept;
diff --git a/headers/enduro2d/utils/xml_utils.hpp b/headers/enduro2d/utils/xml_utils.hpp
index cf47e61a..dbd187ec 100644
--- a/headers/enduro2d/utils/xml_utils.hpp
+++ b/headers/enduro2d/utils/xml_utils.hpp
@@ -10,6 +10,6 @@
 
 #include <3rdparty/pugixml/pugixml.hpp>
 
-namespace e2d { namespace xml_utils
+namespace e2d::xml_utils
 {
-}}
+}
diff --git a/sources/enduro2d/utils/color.cpp b/sources/enduro2d/utils/color.cpp
index 355e7d7a..55a2cf72 100644
--- a/sources/enduro2d/utils/color.cpp
+++ b/sources/enduro2d/utils/color.cpp
@@ -238,7 +238,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace math
+namespace e2d::math
 {
     //
     // approximately
@@ -312,9 +312,9 @@ namespace e2d { namespace math
             || !math::is_finite(c.b)
             || !math::is_finite(c.a);
     }
-}}
+}
 
-namespace e2d { namespace colors
+namespace e2d::colors
 {
     u32 pack_color(const color& c) noexcept {
         return
@@ -331,4 +331,4 @@ namespace e2d { namespace colors
             math::numeric_cast<u8>((argb >>  0) & 0xFF) / 255.f,
             math::numeric_cast<u8>((argb >> 24) & 0xFF) / 255.f);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/color32.cpp b/sources/enduro2d/utils/color32.cpp
index 95909ae0..a75bb62d 100644
--- a/sources/enduro2d/utils/color32.cpp
+++ b/sources/enduro2d/utils/color32.cpp
@@ -238,7 +238,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace math
+namespace e2d::math
 {
     //
     // approximately
@@ -297,9 +297,9 @@ namespace e2d { namespace math
             math::clamp(c.b, cmin.b, cmax.b),
             math::clamp(c.a, cmin.a, cmax.a));
     }
-}}
+}
 
-namespace e2d { namespace colors
+namespace e2d::colors
 {
     u32 pack_color32(const color32& c) noexcept {
         return
@@ -316,4 +316,4 @@ namespace e2d { namespace colors
             math::numeric_cast<u8>((argb >>  0) & 0xFF),
             math::numeric_cast<u8>((argb >> 24) & 0xFF));
     }
-}}
+}
diff --git a/sources/enduro2d/utils/filesystem.cpp b/sources/enduro2d/utils/filesystem.cpp
index e6728f7f..de7fa535 100644
--- a/sources/enduro2d/utils/filesystem.cpp
+++ b/sources/enduro2d/utils/filesystem.cpp
@@ -18,7 +18,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace filesystem
+namespace e2d::filesystem
 {
     bool remove(str_view path) {
         return remove_file(path)
@@ -118,4 +118,4 @@ namespace e2d { namespace filesystem
     bool extract_predef_path(str& dst, predef_path path_type) {
         return impl::extract_predef_path(dst, path_type);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/filesystem_impl/files.hpp b/sources/enduro2d/utils/filesystem_impl/files.hpp
index ebca21e1..f9753645 100644
--- a/sources/enduro2d/utils/filesystem_impl/files.hpp
+++ b/sources/enduro2d/utils/filesystem_impl/files.hpp
@@ -29,8 +29,8 @@
 #  error E2D_FILES_MODE not detected
 #endif
 
-namespace e2d { namespace impl
+namespace e2d::impl
 {
     read_file_uptr make_read_file(str_view path) noexcept;
     write_file_uptr make_write_file(str_view path, bool append) noexcept;
-}}
+}
diff --git a/sources/enduro2d/utils/filesystem_impl/files_posix.cpp b/sources/enduro2d/utils/filesystem_impl/files_posix.cpp
index 2deea908..e6ee5ba5 100644
--- a/sources/enduro2d/utils/filesystem_impl/files_posix.cpp
+++ b/sources/enduro2d/utils/filesystem_impl/files_posix.cpp
@@ -183,7 +183,7 @@ namespace
     };
 }
 
-namespace e2d { namespace impl
+namespace e2d::impl
 {
     read_file_uptr make_read_file(str_view path) noexcept {
         try {
@@ -200,6 +200,6 @@ namespace e2d { namespace impl
             return nullptr;
         }
     }
-}}
+}
 
 #endif
diff --git a/sources/enduro2d/utils/filesystem_impl/files_winapi.cpp b/sources/enduro2d/utils/filesystem_impl/files_winapi.cpp
index 01e0eddd..3d916a4c 100644
--- a/sources/enduro2d/utils/filesystem_impl/files_winapi.cpp
+++ b/sources/enduro2d/utils/filesystem_impl/files_winapi.cpp
@@ -222,7 +222,7 @@ namespace
     };
 }
 
-namespace e2d { namespace impl
+namespace e2d::impl
 {
     read_file_uptr make_read_file(str_view path) noexcept {
         try {
@@ -239,6 +239,6 @@ namespace e2d { namespace impl
             return nullptr;
         }
     }
-}}
+}
 
 #endif
diff --git a/sources/enduro2d/utils/filesystem_impl/filesystem.hpp b/sources/enduro2d/utils/filesystem_impl/filesystem.hpp
index 901453a0..e30a894f 100644
--- a/sources/enduro2d/utils/filesystem_impl/filesystem.hpp
+++ b/sources/enduro2d/utils/filesystem_impl/filesystem.hpp
@@ -10,7 +10,7 @@
 #include <enduro2d/utils/strings.hpp>
 #include <enduro2d/utils/filesystem.hpp>
 
-namespace e2d { namespace filesystem { namespace impl
+namespace e2d::filesystem::impl
 {
     bool remove_file(str_view path);
     bool remove_directory(str_view path);
@@ -23,4 +23,4 @@ namespace e2d { namespace filesystem { namespace impl
     bool trace_directory(str_view path, const trace_func& func);
 
     bool extract_predef_path(str& dst, predef_path path_type);
-}}}
+}
diff --git a/sources/enduro2d/utils/filesystem_impl/filesystem_ios.mm b/sources/enduro2d/utils/filesystem_impl/filesystem_ios.mm
index deb74a85..e7f26ebd 100644
--- a/sources/enduro2d/utils/filesystem_impl/filesystem_ios.mm
+++ b/sources/enduro2d/utils/filesystem_impl/filesystem_ios.mm
@@ -88,7 +88,7 @@ namespace
     }
 }
 
-namespace e2d { namespace filesystem { namespace impl
+namespace e2d::filesystem::impl
 {
     bool remove_file(str_view path) {
         return 0 == ::unlink(make_utf8(path).c_str())
@@ -155,6 +155,6 @@ namespace e2d { namespace filesystem { namespace impl
                 return false;
         }
     }
-}}}
+}
 
 #endif
diff --git a/sources/enduro2d/utils/filesystem_impl/filesystem_linux.cpp b/sources/enduro2d/utils/filesystem_impl/filesystem_linux.cpp
index 65bc8a14..3ed94dc5 100644
--- a/sources/enduro2d/utils/filesystem_impl/filesystem_linux.cpp
+++ b/sources/enduro2d/utils/filesystem_impl/filesystem_linux.cpp
@@ -78,7 +78,7 @@ namespace
     }
 }
 
-namespace e2d { namespace filesystem { namespace impl
+namespace e2d::filesystem::impl
 {
     bool remove_file(str_view path) {
         return 0 == ::unlink(make_utf8(path).c_str())
@@ -145,6 +145,6 @@ namespace e2d { namespace filesystem { namespace impl
                 return false;
         }
     }
-}}}
+}
 
 #endif
diff --git a/sources/enduro2d/utils/filesystem_impl/filesystem_macosx.mm b/sources/enduro2d/utils/filesystem_impl/filesystem_macosx.mm
index 0c35303d..b41e0106 100644
--- a/sources/enduro2d/utils/filesystem_impl/filesystem_macosx.mm
+++ b/sources/enduro2d/utils/filesystem_impl/filesystem_macosx.mm
@@ -88,7 +88,7 @@ namespace
     }
 }
 
-namespace e2d { namespace filesystem { namespace impl
+namespace e2d::filesystem::impl
 {
     bool remove_file(str_view path) {
         return 0 == ::unlink(make_utf8(path).c_str())
@@ -155,6 +155,6 @@ namespace e2d { namespace filesystem { namespace impl
                 return false;
         }
     }
-}}}
+}
 
 #endif
diff --git a/sources/enduro2d/utils/filesystem_impl/filesystem_windows.cpp b/sources/enduro2d/utils/filesystem_impl/filesystem_windows.cpp
index a19b5c25..632a6efd 100644
--- a/sources/enduro2d/utils/filesystem_impl/filesystem_windows.cpp
+++ b/sources/enduro2d/utils/filesystem_impl/filesystem_windows.cpp
@@ -92,7 +92,7 @@ namespace
     }
 }
 
-namespace e2d { namespace filesystem { namespace impl
+namespace e2d::filesystem::impl
 {
     bool remove_file(str_view path) {
         const wstr wide_path = make_wide(path);
@@ -169,6 +169,6 @@ namespace e2d { namespace filesystem { namespace impl
                 return false;
         }
     }
-}}}
+}
 
 #endif
diff --git a/sources/enduro2d/utils/image.cpp b/sources/enduro2d/utils/image.cpp
index f7ac6308..13681e72 100644
--- a/sources/enduro2d/utils/image.cpp
+++ b/sources/enduro2d/utils/image.cpp
@@ -207,7 +207,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace images
+namespace e2d::images
 {
     bool try_load_image(
         image& dst,
@@ -258,4 +258,4 @@ namespace e2d { namespace images
         return try_save_image(src, format, file_data)
             && streams::try_write_tail(file_data, dst);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_impl.hpp b/sources/enduro2d/utils/image_impl/image_impl.hpp
index c36c1616..c9786f1a 100644
--- a/sources/enduro2d/utils/image_impl/image_impl.hpp
+++ b/sources/enduro2d/utils/image_impl/image_impl.hpp
@@ -9,7 +9,7 @@
 #include <enduro2d/utils/image.hpp>
 #include <enduro2d/utils/buffer.hpp>
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_load_image_dds(image& dst, const buffer& src) noexcept;
     bool try_load_image_pvr(image& dst, const buffer& src) noexcept;
@@ -20,4 +20,4 @@ namespace e2d { namespace images { namespace impl
     bool try_save_image_png(const image& src, buffer& dst) noexcept;
     bool try_save_image_pvr(const image& src, buffer& dst) noexcept;
     bool try_save_image_tga(const image& src, buffer& dst) noexcept;
-}}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_reader_dds.cpp b/sources/enduro2d/utils/image_impl/image_reader_dds.cpp
index 49548705..3ce8c356 100644
--- a/sources/enduro2d/utils/image_impl/image_reader_dds.cpp
+++ b/sources/enduro2d/utils/image_impl/image_reader_dds.cpp
@@ -6,11 +6,11 @@
 
 #include "image_impl.hpp"
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_load_image_dds(image& dst, const buffer& src) noexcept {
         //TODO(BlackMat): implme
         E2D_UNUSED(dst, src);
         return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_reader_pvr.cpp b/sources/enduro2d/utils/image_impl/image_reader_pvr.cpp
index e151c84a..e39c438b 100644
--- a/sources/enduro2d/utils/image_impl/image_reader_pvr.cpp
+++ b/sources/enduro2d/utils/image_impl/image_reader_pvr.cpp
@@ -6,11 +6,11 @@
 
 #include "image_impl.hpp"
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_load_image_pvr(image& dst, const buffer& src) noexcept {
         //TODO(BlackMat): implme
         E2D_UNUSED(dst, src);
         return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_reader_stb.cpp b/sources/enduro2d/utils/image_impl/image_reader_stb.cpp
index ada3252c..c20e73b4 100644
--- a/sources/enduro2d/utils/image_impl/image_reader_stb.cpp
+++ b/sources/enduro2d/utils/image_impl/image_reader_stb.cpp
@@ -16,11 +16,11 @@
 #define STBI_ONLY_TGA
 #define STBI_ONLY_JPEG
 
-#define STBI_FREE(ptr)          std::free(ptr)
-#define STBI_MALLOC(size)       std::malloc(size)
+#define STBI_FREE(ptr) std::free(ptr)
+#define STBI_MALLOC(size) std::malloc(size)
 #define STBI_REALLOC(ptr,nsize) std::realloc(ptr, nsize)
 
-#define STBI_ASSERT(expr)       E2D_ASSERT(expr)
+#define STBI_ASSERT(expr) E2D_ASSERT(expr)
 
 #define STB_IMAGE_IMPLEMENTATION
 #include <3rdparty/stb/stb_image.h>
@@ -77,7 +77,7 @@ namespace
     }
 }
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_load_image_stb(image& dst, const buffer& src) noexcept {
         v2u img_size;
@@ -86,4 +86,4 @@ namespace e2d { namespace images { namespace impl
         return img_ptr
             && image_from_stb_description(dst, img_ptr, img_size, img_channels);
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_writer_dds.cpp b/sources/enduro2d/utils/image_impl/image_writer_dds.cpp
index 33e025f8..e8ec7e2e 100644
--- a/sources/enduro2d/utils/image_impl/image_writer_dds.cpp
+++ b/sources/enduro2d/utils/image_impl/image_writer_dds.cpp
@@ -27,7 +27,7 @@ namespace
     }
 }
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_save_image_dds(const image& src, buffer& dst) noexcept {
         E2D_UNUSED(src, dst);
@@ -37,4 +37,4 @@ namespace e2d { namespace images { namespace impl
         }
         return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_writer_pvr.cpp b/sources/enduro2d/utils/image_impl/image_writer_pvr.cpp
index cc271e58..011190a6 100644
--- a/sources/enduro2d/utils/image_impl/image_writer_pvr.cpp
+++ b/sources/enduro2d/utils/image_impl/image_writer_pvr.cpp
@@ -33,7 +33,7 @@ namespace
     }
 }
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_save_image_pvr(const image& src, buffer& dst) noexcept {
         E2D_UNUSED(src, dst);
@@ -43,4 +43,4 @@ namespace e2d { namespace images { namespace impl
         }
         return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/image_impl/image_writer_stb.cpp b/sources/enduro2d/utils/image_impl/image_writer_stb.cpp
index 2cffa5fa..6fdb258b 100644
--- a/sources/enduro2d/utils/image_impl/image_writer_stb.cpp
+++ b/sources/enduro2d/utils/image_impl/image_writer_stb.cpp
@@ -8,11 +8,11 @@
 
 #define STBI_WRITE_NO_STDIO
 
-#define STBIW_FREE(ptr)          std::free(ptr)
-#define STBIW_MALLOC(size)       std::malloc(size)
+#define STBIW_FREE(ptr) std::free(ptr)
+#define STBIW_MALLOC(size) std::malloc(size)
 #define STBIW_REALLOC(ptr,nsize) std::realloc(ptr, nsize)
 
-#define STBIW_ASSERT(expr)       E2D_ASSERT(expr)
+#define STBIW_ASSERT(expr) E2D_ASSERT(expr)
 
 #define STB_IMAGE_WRITE_IMPLEMENTATION
 #include <3rdparty/stb/stb_image_write.h>
@@ -41,7 +41,7 @@ namespace
     }
 }
 
-namespace e2d { namespace images { namespace impl
+namespace e2d::images::impl
 {
     bool try_save_image_jpg(const image& src, buffer& dst) noexcept {
         int img_w = math::numeric_cast<int>(src.size().x);
@@ -96,4 +96,4 @@ namespace e2d { namespace images { namespace impl
         }
         return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/json_utils.cpp b/sources/enduro2d/utils/json_utils.cpp
index d55a2ee6..2fe767b6 100644
--- a/sources/enduro2d/utils/json_utils.cpp
+++ b/sources/enduro2d/utils/json_utils.cpp
@@ -638,7 +638,7 @@ namespace
     }
 }
 
-namespace e2d { namespace json_utils
+namespace e2d::json_utils
 {
     void add_common_schema_definitions(rapidjson::Document& schema) {
         schema.AddMember(
@@ -648,9 +648,9 @@ namespace e2d { namespace json_utils
                 schema.GetAllocator()).Move(),
             schema.GetAllocator());
     }
-}}
+}
 
-namespace e2d { namespace json_utils
+namespace e2d::json_utils
 {
     bool try_parse_value(const rapidjson::Value& root, v2i& v) noexcept {
         v2i tv;
@@ -868,10 +868,10 @@ namespace e2d { namespace json_utils
         }
         try {
             s = make_utf8(root.GetString());
+            return true;
         } catch (...) {
             return false;
         }
-        return true;
     }
 
     bool try_parse_value(const rapidjson::Value& root, wstr& s) noexcept {
@@ -880,10 +880,10 @@ namespace e2d { namespace json_utils
         }
         try {
             s = make_wide(root.GetString());
+            return true;
         } catch (...) {
             return false;
         }
-        return true;
     }
 
     bool try_parse_value(const rapidjson::Value& root, str16& s) noexcept {
@@ -892,10 +892,10 @@ namespace e2d { namespace json_utils
         }
         try {
             s = make_utf16(root.GetString());
+            return true;
         } catch (...) {
             return false;
         }
-        return true;
     }
 
     bool try_parse_value(const rapidjson::Value& root, str32& s) noexcept {
@@ -904,10 +904,10 @@ namespace e2d { namespace json_utils
         }
         try {
             s = make_utf32(root.GetString());
+            return true;
         } catch (...) {
             return false;
         }
-        return true;
     }
 
     bool try_parse_value(const rapidjson::Value& root, str_hash& s) noexcept {
@@ -916,9 +916,9 @@ namespace e2d { namespace json_utils
         }
         try {
             s = make_hash(root.GetString());
+            return true;
         } catch (...) {
             return false;
         }
-        return true;
     }
-}}
+}
diff --git a/sources/enduro2d/utils/mesh.cpp b/sources/enduro2d/utils/mesh.cpp
index 5950b88d..393447aa 100644
--- a/sources/enduro2d/utils/mesh.cpp
+++ b/sources/enduro2d/utils/mesh.cpp
@@ -295,7 +295,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace meshes
+namespace e2d::meshes
 {
     bool try_load_mesh(
         mesh& dst,
@@ -312,4 +312,4 @@ namespace e2d { namespace meshes
         return streams::try_read_tail(file_data, src)
             && try_load_mesh(dst, file_data);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/mesh_impl/mesh_impl.hpp b/sources/enduro2d/utils/mesh_impl/mesh_impl.hpp
index 8563b410..2b93aeb5 100644
--- a/sources/enduro2d/utils/mesh_impl/mesh_impl.hpp
+++ b/sources/enduro2d/utils/mesh_impl/mesh_impl.hpp
@@ -9,7 +9,7 @@
 #include <enduro2d/utils/mesh.hpp>
 #include <enduro2d/utils/buffer.hpp>
 
-namespace e2d { namespace meshes { namespace impl
+namespace e2d::meshes::impl
 {
     bool try_load_mesh_e2d(mesh& dst, const buffer& src) noexcept;
-}}}
+}
diff --git a/sources/enduro2d/utils/mesh_impl/mesh_reader_e2d.cpp b/sources/enduro2d/utils/mesh_impl/mesh_reader_e2d.cpp
index d6217aee..be9d5fe7 100644
--- a/sources/enduro2d/utils/mesh_impl/mesh_reader_e2d.cpp
+++ b/sources/enduro2d/utils/mesh_impl/mesh_reader_e2d.cpp
@@ -112,7 +112,7 @@ namespace
     }
 }
 
-namespace e2d { namespace meshes { namespace impl
+namespace e2d::meshes::impl
 {
     bool try_load_mesh_e2d(mesh& dst, const buffer& src) noexcept {
         try {
@@ -121,8 +121,7 @@ namespace e2d { namespace meshes { namespace impl
                 && check_signature(stream)
                 && load_mesh(dst, stream);
         } catch (...) {
-            // nothing
+            return false;
         }
-        return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/path.cpp b/sources/enduro2d/utils/path.cpp
index 9cf9d264..df1a0923 100644
--- a/sources/enduro2d/utils/path.cpp
+++ b/sources/enduro2d/utils/path.cpp
@@ -37,7 +37,7 @@ namespace
     }
 }
 
-namespace e2d { namespace path
+namespace e2d::path
 {
     str combine(str_view lhs, str_view rhs) {
         if ( lhs.empty() || is_absolute(rhs) ) {
@@ -132,4 +132,4 @@ namespace e2d { namespace path
     bool is_relative(str_view path) noexcept {
         return !is_absolute(path);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/shape.cpp b/sources/enduro2d/utils/shape.cpp
index a16525ab..baf4958c 100644
--- a/sources/enduro2d/utils/shape.cpp
+++ b/sources/enduro2d/utils/shape.cpp
@@ -220,7 +220,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace shapes
+namespace e2d::shapes
 {
     bool try_load_shape(
         shape& dst,
@@ -237,4 +237,4 @@ namespace e2d { namespace shapes
         return streams::try_read_tail(file_data, src)
             && try_load_shape(dst, file_data);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/shape_impl/shape_impl.hpp b/sources/enduro2d/utils/shape_impl/shape_impl.hpp
index b3016927..e5e4affa 100644
--- a/sources/enduro2d/utils/shape_impl/shape_impl.hpp
+++ b/sources/enduro2d/utils/shape_impl/shape_impl.hpp
@@ -9,7 +9,7 @@
 #include <enduro2d/utils/shape.hpp>
 #include <enduro2d/utils/buffer.hpp>
 
-namespace e2d { namespace shapes { namespace impl
+namespace e2d::shapes::impl
 {
     bool try_load_shape_e2d(shape& dst, const buffer& src) noexcept;
-}}}
+}
diff --git a/sources/enduro2d/utils/shape_impl/shape_reader_e2d.cpp b/sources/enduro2d/utils/shape_impl/shape_reader_e2d.cpp
index c6f85a0a..ae9e8b63 100644
--- a/sources/enduro2d/utils/shape_impl/shape_reader_e2d.cpp
+++ b/sources/enduro2d/utils/shape_impl/shape_reader_e2d.cpp
@@ -94,7 +94,7 @@ namespace
     }
 }
 
-namespace e2d { namespace shapes { namespace impl
+namespace e2d::shapes::impl
 {
     bool try_load_shape_e2d(shape& dst, const buffer& src) noexcept {
         try {
@@ -103,8 +103,7 @@ namespace e2d { namespace shapes { namespace impl
                 && check_signature(stream)
                 && load_shape(dst, stream);
         } catch (...) {
-            // nothing
+            return false;
         }
-        return false;
     }
-}}}
+}
diff --git a/sources/enduro2d/utils/streams.cpp b/sources/enduro2d/utils/streams.cpp
index 91baa1b8..820e10b8 100644
--- a/sources/enduro2d/utils/streams.cpp
+++ b/sources/enduro2d/utils/streams.cpp
@@ -211,7 +211,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace streams
+namespace e2d::streams
 {
     bool try_read_tail(str& dst, const input_stream_uptr& stream) noexcept {
         return stream
@@ -244,4 +244,4 @@ namespace e2d { namespace streams
                 .success()
             : false;
     }
-}}
+}
diff --git a/sources/enduro2d/utils/strings.cpp b/sources/enduro2d/utils/strings.cpp
index 812d3b31..b3152aaa 100644
--- a/sources/enduro2d/utils/strings.cpp
+++ b/sources/enduro2d/utils/strings.cpp
@@ -260,7 +260,7 @@ namespace e2d
     }
 }
 
-namespace e2d { namespace strings
+namespace e2d::strings
 {
     namespace impl
     {
@@ -337,4 +337,4 @@ namespace e2d { namespace strings
         return input.length() >= test.length()
             && 0 == input.compare(input.length() - test.length(), test.length(), test);
     }
-}}
+}
diff --git a/sources/enduro2d/utils/url.cpp b/sources/enduro2d/utils/url.cpp
index c4e37250..b44139ef 100644
--- a/sources/enduro2d/utils/url.cpp
+++ b/sources/enduro2d/utils/url.cpp
@@ -72,8 +72,8 @@ namespace e2d
         assign(schemepath);
     }
 
-    url::url(str_view scheme, str_view path) noexcept {
-        assign(scheme, path);
+    url::url(str scheme, str path) noexcept {
+        assign(std::move(scheme), std::move(path));
     }
 
     url& url::assign(url&& other) noexcept {
@@ -96,9 +96,9 @@ namespace e2d
         return assign(std::move(nscheme), std::move(npath));
     }
 
-    url& url::assign(str_view scheme, str_view path) noexcept {
-        scheme_ = scheme;
-        path_ = path;
+    url& url::assign(str scheme, str path) noexcept {
+        scheme_ = std::move(scheme);
+        path_ = std::move(path);
         return *this;
     }
 
diff --git a/sources/enduro2d/utils/xml_utils.cpp b/sources/enduro2d/utils/xml_utils.cpp
index 86ca9132..dd921661 100644
--- a/sources/enduro2d/utils/xml_utils.cpp
+++ b/sources/enduro2d/utils/xml_utils.cpp
@@ -11,6 +11,6 @@ namespace
     using namespace e2d;
 }
 
-namespace e2d { namespace xml_utils
+namespace e2d::xml_utils
 {
-}}
+}
diff --git a/untests/sources/untests_core/vfs.cpp b/untests/sources/untests_core/vfs.cpp
index 0cfd8d91..8309297f 100644
--- a/untests/sources/untests_core/vfs.cpp
+++ b/untests/sources/untests_core/vfs.cpp
@@ -8,8 +8,8 @@
 using namespace e2d;
 
 TEST_CASE("vfs"){
-    const str_view file_path = "vfs_file_name";
-    const str_view nofile_path = "vfs_file_name2";
+    const str file_path = "vfs_file_name";
+    const str nofile_path = "vfs_file_name2";
     {
         REQUIRE(filesystem::remove_file(nofile_path));
         REQUIRE(filesystem::create_file(file_path));