UnicodeConvStd v2.0.1

Convenient easy-to-use and efficient helper functions to convert between Unicode UTF-16 and UTF-8 using std::wstring and std::string (and their respective "string views").

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This project contains a header-only C++ file that implements a couple of functions to simply, efficiently, and conveniently convert Unicode text between UTF-16 and UTF-8, using C++ Standard Library's std::wstring and std::string classes and direct Win32 API calls.

• std::wstring is used to store UTF-16-encoded text.
• std::string is used to store UTF-8-encoded text.

Input strings are represented using string views, in particular:

• std::wstring_view is used as input UTF-16-encoded text.
• std::string_view is used as input UTF-8-encoded text.

The exported functions are:

// Convert from UTF-16 to UTF-8
std::string Utf8FromUtf16(std::wstring_view utf16)
    
// Convert from UTF-8 to UTF-16
std::wstring Utf16FromUtf8(std::string_view utf8)

These functions live under the UnicodeConvStd namespace.

This code compiles cleanly at warning level 4 (/W4) on both 32-bit and 64-bit builds, with Visual Studio 2019 in C++17 mode.

Just #include "UnicodeConvStd.hpp" in your projects, and enjoy!

Related blog posts:

• https://giodicanio.com/2025/10/27/converting-between-unicode-utf-16-and-utf-8-in-windows-c-plus-plus-code/
• https://giodicanio.com/2023/10/03/converting-between-unicode-utf-16-and-utf-8-using-c-plus-plus-standard-library-strings-and-direct-win32-api-calls/