D has native support for 'delegates'; closures, essentially. Function literals that reference objects from an outer scope are delegates, and ABI-compatible wit

D has native support for 'delegates'; closures, essentially. Function literals that reference objects from an outer scope are delegates, and ABI-compatible with other delegates. Regular function pointers can trivially be converted to delegates, so if you want to store function pointers, you should store delegates instead and convert transparently as needed. You can't pass delegates into C functions (because they're only in the D abi, not the C abi), though most C libraries that take a callback also take a 'state' pointer that you can use instead. Tl;dr: it's a bit complicated, especially wrt communication with c libraries, but in general they're interchangeable with other functions.