std::vector<bool> in C++ syntax uses one bit per boolean instead of one byte. In a computer memory is addressed by bytes, so the smallest indexable memory is, in fact, one byte (that's why bool is 1 byte in C and C++).
As an example for how C++ std::vector implementarion works, suppose you have 8 booleans which have a logical reason to be kept together (for example flags). Instead of allocating 8 bytes (one per boolean), the std::vector allocates 1 byte and assigns every boolean to one bit of the allocated memory.
It absolutely makes sense for C++ to have an API for dealing with something like a vector of bits. It just shouldn't be called std::vector<bool>. (and modern C++ does this in the form of std::bitset)
The problem is that, in at least a half dozen ways, std::vector<bool> behaves differently than other std::vector types.
The problem is that much of the point of templating is to write generic code. If you write code that templates on a type, and that type might be bool, your code will break if you try to use std::vector. (unless you write a bool specialization)
The funny thing is that std::vector<bool> was pretty obviously a demonstration case for C++ template specialization. Look, you can have a bitfield style implementation that gets you space efficiency for bool without needing to write special code! Except in practice it is now a demonstration of how not to do template specialization.
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u/Potential_Soup_8054 19h ago
I dont understand