working version with requested funcs.

P.S: W.I.P template SFINAE protection for unwanted equations

openVulkanoCpp/Data/Containers/String.hpp

@@ -7,10 +7,12 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 #include <c4/substr.hpp>
 #include <c4/substr_fwd.hpp>
 #include <c4/format.hpp>
 #include <c4/charconv.hpp>
+#include <utf8.h>
 #include <type_traits>
 
 namespace OpenVulkano
@@ -21,6 +23,7 @@ namespace OpenVulkano
 		String() = default;
 		String(const char* str) : m_string(str) {}
 		String(const std::string& str) : m_string(str) {}
+		String(const std::string_view& str) : m_string(str) {}
 		String(const String& other) : m_string(other.m_string) {}
 		String(String&& other) noexcept : m_string(std::move(other.m_string)) {}
 		~String() = default;
@@ -30,17 +33,31 @@ namespace OpenVulkano
 			m_string = other;
 			return *this;
 		}
+
 		template<typename T> String& operator=(T&& other)
 		{
 			m_string = std::move(other);
 			return *this;
 		}
 
+		template<typename T> String& operator=(const String& other)
+		{
+			m_string = other.m_string;
+			return *this;
+		}
+
 		template<typename T> String& operator+=(const T& other)
 		{
 			m_string += other;
 			return *this;
 		}
+
+		template<typename T> String& operator+=(const String& other)
+		{
+			m_string += other.m_string;
+			return *this;
+		}
+
 		template<typename T> String operator+(const T& other) const { return m_string + other; }
 		String operator+(const String& other) const { return m_string + other.m_string; }
 
@@ -50,19 +67,28 @@ namespace OpenVulkano
 		operator std::string() const { return m_string; }
 		explicit operator std::string_view() const { return m_string; }
 
+		const char& operator[](size_t index) const noexcept { return m_string[index]; }
+		const char& At(size_t index) const { return m_string.at(index); }
 		const char* CharString() const { return m_string.c_str(); }
 		const char* Data() { return m_string.data(); }
 		size_t Length() const { return m_string.length(); }
 		size_t Size() const { return m_string.size(); }
+		bool Empty() const { return m_string.empty(); }
+		size_t Capacity() const { return m_string.capacity(); }
+		size_t CharCount() const { return utf8::distance(m_string.begin(), m_string.end()); }
 
 		char& Front() { return m_string.front(); }
 		char& Back() { return m_string.back(); }
 		void PopBack() { m_string.pop_back(); }
 		void Clear() { m_string.clear(); }
 		void Shrink() { m_string.shrink_to_fit(); }
-		String Substring(size_t start, size_t end) const { return m_string.substr(start, end); }
+		String SubString(size_t start, size_t end) const { return m_string.substr(start, end); }
+		bool StartsWith(const String& str) const { return m_string.find(str) == 0; }
+		bool EndsWith(const String& str) const { return m_string.rfind(str) == m_string.size() - str.Size(); }
+		bool Contains(const String& str) const { return m_string.find(str) != std::string::npos; }
 
 		size_t FindStartIndexOf(const String& str) const { return m_string.find(str); }
+		size_t FindEndIndexOf(const String& str) const { return m_string.rfind(str); }
 
 		String& Trim() noexcept
 		{
@@ -72,6 +98,20 @@ namespace OpenVulkano
 			return *this;
 		}
 
+		String& TrimFront()
+		{
+			size_t start = m_string.find_first_not_of(" \t\n");
+			m_string = m_string.substr(start);
+			return *this;
+		}
+
+		String& TrimBack()
+		{
+			size_t end = m_string.find_last_not_of(" \t\n");
+			m_string = m_string.substr(0, end + 1);
+			return *this;
+		}
+
 		void ToUpper() noexcept
 		{
 			for (char& c: m_string)
@@ -95,7 +135,7 @@ namespace OpenVulkano
 		}
 
 		// Makes "i am a string" to "I Am A String" also need a better name for the function
-		void ToUpperStarters()
+		void FirstLettersUpper()
 		{
 			for (size_t i = 0; i < m_string.size(); ++i)
 			{
@@ -114,9 +154,19 @@ namespace OpenVulkano
 			return value;
 		}
 
+		// iterators
+		std::string::iterator begin() { return m_string.begin(); }
+		std::string::iterator end() { return m_string.end(); }
+		std::string::const_iterator cbegin() const { return m_string.cbegin(); }
+		std::string::const_iterator cend() const { return m_string.cend(); }
+		std::string::reverse_iterator rbegin() { return m_string.rbegin(); }
+		std::string::reverse_iterator rend() { return m_string.rend(); }
+		std::reverse_iterator<std::string::const_iterator> crbegin() const { return m_string.crbegin(); }
+		std::reverse_iterator<std::string::const_iterator> crend() const { return m_string.crend(); }
+
 	private:
 		std::string m_string;
 	};
 
-	template<typename T> String operator+(const T& lhs, const String& rhs) noexcept { return lhs + rhs; }
+	template<typename T> String operator+(const T& lhs, const String& rhs) noexcept { return String(lhs) + rhs; }
 }

tests/StringTest.cpp

@@ -74,6 +74,15 @@ TEST_CASE("String")
 		String str8("Hello");
 		String str9 = str8 + String(" World");
 		REQUIRE(str9 == "Hello World");
+
+		String str10 = String("Hello") + " World";
+		REQUIRE(str10 == "Hello World");
+
+		String str11 = String("Hello") + std::string(" World");
+		REQUIRE(str11 == "Hello World");
+
+		String str12 = std::string("Hello") + String(" World");
+		REQUIRE(str12 == "Hello World");
 	}
 
 	SECTION("Comparison")
@@ -110,15 +119,15 @@ TEST_CASE("String")
 		REQUIRE(str2 == "hello world");
 
 		String str3("Georg will save us all from our doom");
-		str3.ToUpperStarters();
+		str3.FirstLettersUpper();
 		REQUIRE(str3 == "Georg Will Save Us All From Our Doom");
 	}
 
 	SECTION("Substring")
 	{
 		String str1("Hello World");
-		REQUIRE(str1.Substring(0, 5) == "Hello");
+		REQUIRE(str1.SubString(0, 5) == "Hello");
-		REQUIRE(str1.Substring(6, 11) == "World");
+		REQUIRE(str1.SubString(6, 11) == "World");
 	}
 
 	SECTION("FromString")