billboard example error fix + string wrapper first implementation

tests/StringTest.cpp

@@ -0,0 +1,89 @@
+/*
+* This Source Code Form is subject to the terms of the Mozilla Public
+* License, v. 2.0. If a copy of the MPL was not distributed with this
+* file, You can obtain one at https://mozilla.org/MPL/2.0/.
+*/
+
+#include <catch2/catch_all.hpp>
+
+#include "Data/Containers/String.hpp"
+
+using namespace OpenVulkano;
+
+TEST_CASE("String")
+{
+	SECTION("Constructors")
+	{
+		String str1;
+		REQUIRE(str1 == "");
+
+		String str2("Hello");
+		REQUIRE(str2 == "Hello");
+
+		String str3(std::string("World"));
+		REQUIRE(str3 == "World");
+
+		String str4(str2);
+		REQUIRE(str4 == "Hello");
+
+		String str5(std::move(str3));
+		REQUIRE(str5 == "World");
+	}
+
+	SECTION("Assignment")
+	{
+		String str1;
+		str1 = "Hello";
+		REQUIRE(str1 == "Hello");
+
+		String str2;
+		str2 = std::string("World");
+		REQUIRE(str2 == "World");
+
+		String str3;
+		str3 = str1;
+		REQUIRE(str3 == "Hello");
+
+		String str4;
+		str4 = std::move(str2);
+		REQUIRE(str4 == "World");
+	}
+
+	SECTION("Concatenation")
+	{
+		String str1("Hello");
+		str1 += " World";
+		REQUIRE(str1 == "Hello World");
+
+		String str2("Hello");
+		String str3 = str2 + " World";
+		REQUIRE(str3 == "Hello World");
+
+		String str4("Hello");
+		str4 += std::string(" World");
+		REQUIRE(str4 == "Hello World");
+
+		String str5("Hello");
+		String str6 = str5 + std::string(" World");
+		REQUIRE(str6 == "Hello World");
+
+		String str7("Hello");
+		str7 += String(" World");
+		REQUIRE(str7 == "Hello World");
+
+		String str8("Hello");
+		String str9 = str8 + String(" World");
+		REQUIRE(str9 == "Hello World");
+	}
+
+	SECTION("Comparison")
+	{
+		String str1("Hello");
+		REQUIRE(str1 == "Hello");
+		REQUIRE(str1 != "World");
+
+		String str2("World");
+		REQUIRE(str2 == "World");
+		REQUIRE(str2 != "Hello");
+	}
+}