module cipher; private import std.range : isInputRange, ElementType, chooseAmong; private import salsa20; private import chacha20; import std.stdio; public: enum Cipher { salsa20, chacha20 } auto cipherFunction(R)(R range, ubyte[32] key, ubyte[8] nonce, Cipher cipher) if(isInputRange!R && is(ElementType!R : ubyte)) { return chooseAmong(cipher, range.salsa20Cipher(key, nonce), range.chacha20Cipher(key, nonce)); }