colorize_index has different values in different translation units

[ZbigniewRA]

Each translation unit contains it's own copy of the colorize_index static variable.
This is a normal property of static variables declared on a namespace level (which is a very different thing than static variables declared in a class or inside a function).
As a result colorize_index is initialized multiple times, and therefore each translation unit gets it's own, different colorize_index value.
Everything works as long as code that uses it is in one translation unit. Everything breaks if code is separated between translation units,
In my case there was no problem in debug builds, but in optimized builds (on g++/Linux and Visual C++/Windows), where code is heavily inlined, problems started to appear.

One solution to that problem could be storing colorize_index as a static variable inside a templated class:

        template<typename T>
        struct ColorizeIndexWrapper
        {
            static int colorize_index;
        };

        template<typename T>
        int ColorizeIndexWrapper<T>::colorize_index = std::ios_base::xalloc();

        // Usage:
        _internal::ColorizeIndexWrapper<int>::colorize_index

[ikalnytskyi]

Hey @ZbigniewRA,

Thanks for reporting this! I wonder, what have I been thinking when I was creating static global variables in the header file. :)

I can easily reproduce this issue with any optimization level on GCC 10.2.0, and -O2 on Clang 11.0.1. I'll work on the patch.