Why delete can perform on pointers to const while free cannot?

Question

I\'ve just noticed that the pointers passed to delete can be const qualified while those passed to free cannot. That is really a surprise

Answer 1

free is C function. Its signature is 20-30 years old, from times where there were no const in C language (and there was no C++ language as well). C++ compiler treats free like every other function, and can't let it accept const pointer without cast, because free could possibly change object pointed. Actually, it does, as well as delete, but C++ doesn't know that free is used for memory management.