add array.h/cpp

cmake/check-from_chars.cmake

@@ -0,0 +1,7 @@
+message(STATUS "Checking that std::from_chars for floats is supported by the C++ library")
+try_compile(FROM_CHARS_WORKS "${CMAKE_BINARY_DIR}" "${CMAKE_CURRENT_LIST_DIR}/check-from_chars.cpp")
+if(FROM_CHARS_WORKS)
+	message(STATUS "Checking that std::from_chars for floats is supported by the C++ library - yes")
+else()
+	message(STATUS "Checking that std::from_chars for floats is supported by the C++ library - NO")
+endif()

cmake/check-from_chars.cpp

@@ -0,0 +1,8 @@
+#include <charconv>
+
+int main()
+{
+	const char str[] = "1.2345e3";
+	float num;
+	std::from_chars(str, str + sizeof str - 1, num);
+}