如何将 char* 转换为 std::u8string？

Question

Intro

If I catch an exception, I want to convert the error message, which is returned as a C-style string by the what() method, into a std::u8string (a UTF-8 string). For example: std::u8string(error.what());

Problem

How can I convert a char* into a std::u8string ?

Additional Information

• I only catch exceptions from the standard library, boost and eigen.
• My application is Windows dependent, so the solution doesn't need to be portable.

Answer 1

You can use the constructor that takes a beginning and an ending iterator for the sequence that defines the string.

#include <cstring>

// ...

auto cstr=error.what();

std::u8string str{cstr, cstr+strlen(cstr)};