Gensym for D

gensym.d

// Mixin to generate a new identifier that won't repeat within a scope
enum gensym(string prefix = "_gensym") =
	`"` ~ prefix ~ `" ~ __traits(identifier, {})["__lambda".length .. $]`;

// Works multiple times on the same line
unittest
{
	enum sym1 = mixin(gensym!()); enum sym2 = mixin(gensym!());
	static assert(sym1 != sym2);
	
	mixin("int ", sym1, " = 123, ", sym2, " = 456;");
	assert(mixin(sym1) == 123);
	assert(mixin(sym2) == 456);
}