Two key points stand out:
- No implementation of the STL is readable without an understanding of the goals, rationale, benefits and limitations of the language itself, and general approach.
- Most implementations are readable once you have a deep understanding of (1) because the code is self-documenting on those premises. You might not like the formatting, but that really should be the least of your problems.
As a side note, you might have more success with the MSVC version because it's not trying to target multiple as many compilers. Compiler bugs and implementation-defined behavior result in various subtle workarounds. As those workarounds grow in number (as certainly happens when you add more compilers), the code can get gross fast.
