[fhgffy]

containers::bitset::operator<< uses unformatted write(), so it leaves the stream's field width for the next insertion. For example, std::setfill('_') << std::setw(6) << bitset{Color::RED} << '!' produces RED_____! instead of ___RED!.

Insert a basic_string_view matching the stream's character traits as one formatted field. This respects alignment and fill, consumes the field width, and preserves the complete name's length. Regression tests cover left/right alignment, a width smaller than the name, empty bitsets, custom traits, and wide-character aliases.

Validation on Windows with MinGW GCC 15.1.0 and CMake 4.3.2:

• The minimal reproducer and the new project regression fail on the unchanged base ccb76393; the reproducer passes after the fix.
• Release CMake build with the project's strict warnings; CTest passes all 28 available cases across C++17, C++20, C++23, and C++26 compiler-specific reflection.
• All 9 public headers pass CMake's independent interface-header verification target.
• git diff --check passes.

C++26 standard reflection and C++ modules were not exercised locally.

[Neargye]

@fhgffy
Thanks for the fix! Could you please remove the added comments? The code and test names are clear without them.

[fhgffy]

Removed the comments added by this PR, including the date annotations. The fix and regression tests are unchanged. Rebuilt and ran test_containers-cpp17 and test_wchar_t-cpp17; both pass.

[Neargye]

Thanks for the PR!