[Bug]: clang-21 build error: gtest-printers.h:528:35: error: implicit conversion from 'char8_t' to...

[dokastho]

Describe the issue

/opt/homebrew/include/gtest/gtest-printers.h:528:35: error: implicit conversion from 'char8_t' to 'char32_t' may change the meaning of the represented code unit [-Werror,-Wcharacter-conversion]
  528 |   PrintTo(ImplicitCast_<char32_t>(c), os);
      |           ~~~~~~~~~~~~~           ^
1 error generated.

Latest brew version of gtest does not build with clang 21 on macOS Tahoe:

$ clang --version
Apple clang version 21.0.0 (clang-2100.3.6.4)

Proposed fix:

static cast to the expected type:

replace line 528 with

PrintTo(static_cast<char32_t>(static_cast<unsigned char>(c)), os);

Steps to reproduce the problem

#include "gtest/gtest.h" in any c++ source file with CXX standard 20

What version of GoogleTest are you using?

$ brew info googletest
==> googletest ✔: stable 1.17.0 (bottled), HEAD

What operating system and version are you using?

macOS Tahoe 26.4, build version 25E246

What compiler and version are you using?

$ clang --version
Apple clang version 21.0.0 (clang-2100.3.6.4)

What build system are you using?

$ cmake --version
cmake version 4.3.1

Additional context

Thank you.

[dokastho]

This change is tested locally. Build works and output is as expected.

[scrossuk]

To add to this (since it wasn't explicitly mentioned), the problem occurs when building with Xcode 26.4, which is based on Clang 21.