As far as the respective language standards go, C offers dynamic memory allocation only through the malloc() family, while in C++ the most common form of allocation is performed by ::operator new(). The C-style malloc is also available in C++, and many "baby's first allocator" examples use it as its core allocation function, but I am curious how contemporary compilers implement the actual production operator-new.
Is it just a thin wrapper around malloc(), or is it implemented fundamentally differently on account of the rather different memory allocation behaviour of a typical C++ program compared to a typical C program?
[Edit: I believe the main difference is usually described as follows: A C program has fewer, larger, long-lived allocations, while a C++ program has many, small, short-lived allocations. Feel free to chime in if that's mistaken, but it sounds like one would benefit from taking this into account.]
For a compiler like GCC it would be easy to just have one single core allocation implementation and use that for all relevant languages, so I wonder if there are differences in the details that try to optimize the resulting allocation performance in each language.
Update: Thanks for all the great answers! It looks like in GCC this is completely solved by ptmalloc, and that MSVC also uses malloc at the core. Does anyone know how the MSVC-malloc is implemented?