Sometimes, especially in embedded systems, it is useful to have a bunch of statically allocated heaps. You can see them in a memory map, and the linker will tell you if they don't fit in memory.

There is also the case where you have some raw data from a file or network, that you want to re-interpret as a struct. That is always dangerous with endianness and struct padding, but it is a very common practice. You could always memcpy from a char array to a struct, but that can waste memory.