fix: change the behavior of printf in string op.

- add compiler hint for checking the arguments of printf.
- change the return value of printf. from std::expected to normal value. use C++ exception to indicate error.
	* the error of printf usually caused by programmer. so it can be found when testing program.
	* so i use std::logic_error to indicate this and programmer should fix this before releasing program.
- change the use of encoding convertion. for those cases that convertion must be safe, we unwrap it directly.

src/yycc/macro/printf_checker.hpp

@@ -0,0 +1,28 @@
+#pragma once
+#include "compiler_detector.hpp"
+#include "stl_detector.hpp"
+
+// YYC MARK:
+// This code is copied from Qt project.
+
+#if defined(YYCC_CC_GCC)
+// GCC has its special attribute
+#define YYCC_PRINTF_CHECK_ATTR(A, B) __attribute__((format(gnu_printf, (A), (B))))
+#elif defined(YYCC_CC_CLANG)
+// Clang use its own attribute
+#define YYCC_PRINTF_CHECK_ATTR(A, B) __attribute__((format(printf, (A), (B))))
+#else
+// Other CC do not support this (like MSVC), skip it
+#define YYCC_PRINTF_CHECK_ATTR(A, B)
+#endif
+
+#if defined(YYCC_STL_MSSTL)
+// On Microsoft STL, we can use some mechanisms to check it.
+#include "../windows/import_guard_head.hpp"
+#include <sal.h>
+#include "../windows/import_guard_tail.hpp"
+#define YYCC_PRINTF_CHECK_FMTSTR _Printf_format_string_
+#else
+// Other STL do not have this.
+#define YYCC_PRINTF_CHECK_FMTSTR
+#endif