more general buffer iterators

headers/enduro2d/utils/buffer.hpp

@@ -11,6 +11,18 @@
 namespace e2d
 {
     class buffer final {
+    public:
+        using value_type = u8;
+
+        using pointer = u8*;
+        using const_pointer = const u8*;
+        using reference = u8&;
+        using const_reference = const u8&;
+
+        using iterator = pointer;
+        using const_iterator = const_pointer;
+        using reverse_iterator = std::reverse_iterator<iterator>;
+        using const_reverse_iterator = std::reverse_iterator<const_iterator>;
     public:
         buffer() = default;
 
@@ -23,6 +35,22 @@ namespace e2d
         explicit buffer(std::size_t size);
         buffer(const void* src, std::size_t size);
 
+        iterator begin() noexcept;
+        const_iterator begin() const noexcept;
+        const_iterator cbegin() const noexcept;
+
+        iterator end() noexcept;
+        const_iterator end() const noexcept;
+        const_iterator cend() const noexcept;
+
+        reverse_iterator rbegin() noexcept;
+        const_reverse_iterator rbegin() const noexcept;
+        const_reverse_iterator crbegin() const noexcept;
+
+        reverse_iterator rend() noexcept;
+        const_reverse_iterator rend() const noexcept;
+        const_reverse_iterator crend() const noexcept;
+
         buffer& fill(u8 ch) noexcept;
         buffer& resize(std::size_t nsize);
 
@@ -37,11 +65,6 @@ namespace e2d
         u8* data() noexcept;
         const u8* data() const noexcept;
         std::size_t size() const noexcept;
-
-        const u8* begin() const noexcept;
-        const u8* end() const noexcept;
-        u8* begin() noexcept;
-        u8* end() noexcept;
     private:
         using data_t = std::unique_ptr<u8[]>;
         data_t data_;

sources/enduro2d/utils/buffer.cpp

@@ -32,6 +32,54 @@ namespace e2d
         assign(src, size);
     }
 
+    buffer::iterator buffer::begin() noexcept {
+        return data_.get();
+    }
+
+    buffer::const_iterator buffer::begin() const noexcept {
+        return data_.get();
+    }
+
+    buffer::const_iterator buffer::cbegin() const noexcept {
+        return data_.get();
+    }
+
+    buffer::iterator buffer::end() noexcept {
+        return data_.get() + size_;
+    }
+
+    buffer::const_iterator buffer::end() const noexcept {
+        return data_.get() + size_;
+    }
+
+    buffer::const_iterator buffer::cend() const noexcept {
+        return data_.get() + size_;
+    }
+
+    buffer::reverse_iterator buffer::rbegin() noexcept {
+        return reverse_iterator(end());
+    }
+
+    buffer::const_reverse_iterator buffer::rbegin() const noexcept {
+        return const_reverse_iterator(end());
+    }
+
+    buffer::const_reverse_iterator buffer::crbegin() const noexcept {
+        return const_reverse_iterator(end());
+    }
+
+    buffer::reverse_iterator buffer::rend() noexcept {
+        return reverse_iterator(begin());
+    }
+
+    buffer::const_reverse_iterator buffer::rend() const noexcept {
+        return const_reverse_iterator(begin());
+    }
+
+    buffer::const_reverse_iterator buffer::crend() const noexcept {
+        return const_reverse_iterator(begin());
+    }
+
     buffer& buffer::fill(u8 ch) noexcept {
         if ( data_ && size_) {
             std::memset(data_.get(), ch, size_);
@@ -107,22 +155,6 @@ namespace e2d
     std::size_t buffer::size() const noexcept {
         return size_;
     }
-
-    const u8* buffer::begin() const noexcept {
-        return data_.get();
-    }
-
-    const u8* buffer::end() const noexcept {
-        return data_.get() + size_;
-    }
-    
-    u8* buffer::begin() noexcept {
-        return data_.get();
-    }
-
-    u8* buffer::end() noexcept {
-        return data_.get() + size_;
-    }
 }
 
 namespace e2d

untests/sources/untests_utils/buffer.cpp

@@ -170,6 +170,22 @@ TEST_CASE("buffer") {
         }
     #endif
     }
+    {
+        const u8 data[] = {1,2,3};
+        buffer b(data, std::size(data) * sizeof(data[0]));
+
+        const auto con_str = [](std::string acc, u8 ch){
+            return acc + std::to_string(ch);
+        };
+
+        REQUIRE(std::accumulate(b.begin(), b.end(), std::string(), con_str) == "123");
+        REQUIRE(std::accumulate(std::as_const(b).begin(), std::as_const(b).end(), std::string(), con_str) == "123");
+        REQUIRE(std::accumulate(b.cbegin(), b.cend(), std::string(), con_str) == "123");
+
+        REQUIRE(std::accumulate(b.rbegin(), b.rend(), std::string(), con_str) == "321");
+        REQUIRE(std::accumulate(std::as_const(b).rbegin(), std::as_const(b).rend(), std::string(), con_str) == "321");
+        REQUIRE(std::accumulate(b.crbegin(), b.crend(), std::string(), con_str) == "321");
+    }
 }
 
 TEST_CASE("buffer_view") {