C++ templates and D

cpp.cpp

template<typename T>
struct Foo {
    T value;
    T twice() const { return value * 2; }
};


#if __clang__
[[clang::optnone]]
#elif __GNUC__
__attribute__((optimize("O0")))
#endif
__attribute((used, noinline))
static void instantiate() {
    const auto t = Foo<int>{}.twice();
    (void)t;
}

d.d

extern(C++) {
    struct Foo(T) {
        T value;
        T twice() const;
    }
}

void main() {
    import std.stdio;
    auto f = Foo!int(3);
    writeln("f: ", f);
    writeln("f.twice: ", f.twice);
}