ifconstexpr.cpp

#include <cstdio>
#include <type_traits>

using namespace Platform;

void doTheThing(const wchar_t* string)
{
    printf("%ws\n", string);
}

template <typename T1, typename T2>
void CatTheThing(const T1& t1, const T2& t2)
{
    if constexpr(std::is_same_v<T1, Platform::String^> &&
                 std::is_same_v<T2, Platform::String^>)
    {
        printf("PlatformString-PlatformString\n");
        doTheThing(Platform::String::Concat(t1, t2)->Data());
    }
    else if constexpr(!std::is_same_v<T1, Platform::String^> &&
                      std::is_same_v<T2, Platform::String^>)
    {
        printf("T-PlatformString\n");        
        doTheThing(Platform::String::Concat(ref new Platform::String(t1), t2)->Data());        
    } 
    else if constexpr(std::is_same_v<T1, Platform::String^> &&
                      !std::is_same_v<T2, Platform::String^>)
    {
        printf("PlatformString-T\n");        
        doTheThing(Platform::String::Concat(t1, ref new Platform::String(t2))->Data());        
    } 
    else
    {
        printf("T-T\n");        
        doTheThing(Platform::String::Concat(ref new Platform::String(t1), ref new Platform::String(t2))->Data());        
    }
}

int main(Platform::Array<Platform::String^>^)
{
	CatTheThing(L"RawString", L"RawString");

	auto str = L"RawString";
	auto str2 = ref new Platform::String(L"PlatformString");
	CatTheThing(str, str2);

	CatTheThing(str2, L"RawString");
	
	auto str3 = ref new Platform::String(L"PlatformString");
	CatTheThing(str2, str3);
}