"std::string_view" is not available in C++11

[halfTree-dev]

My C++ dev environment is MinGW 8.0.1, CMake 3.31, C++11 standard. Things goes wrong when I imported the guid.hpp as head file. In guid.hpp, Line 55, which uses a class called "string_view" is only available in C++17 or higher version.

	explicit Guid(const std::array<unsigned char, 16> &bytes);
	explicit Guid(std::array<unsigned char, 16> &&bytes);

	explicit Guid(std::string_view fromString);
	Guid();

This should be mentioned in the README, so we could prepare a proper environment for this. Anyway, what should I do if I want to use the library in C++11?