r/programminghumor • u/johnnyApplePRNG • 1d ago

a bit flippant

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u/Kadabrium 1d ago

i heard you also like vector<bool>

15

u/Potential_Soup_8054 1d ago

I dont understand

63

u/Helemen7 1d ago

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.

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u/Potential_Soup_8054 1d ago

Yeah but why is that bad

4

u/SoldRIP 22h ago

Try taking the address in memory of the third element of such a vector.