Leedehai questions

• C++ polymorphism: how to test if a class derived from another base class?
• C++: SFINAE to differentiate fill and range constructors?
• What are the common problems in switching from GCC to Clang?
• CPU cache: does the distance between two address needs to be smaller than 8 bytes to have cache advantage?
• LLVM code generator: is Machine code representation machine-agnostic?
• Why does LLVM choose open-addressing hash table to implement llvm::StringMap?
• How to define a Hash class for custom std::basic_string<> specialization class just like std::string?
• C++ SFINAE with decltype: substitution failure becomes an error?
• Why don't memory allocators actively return freed memory to the OS?
• What is the difference between Google's breakpad and crashpad libraries?

Leedehai answers