How do I make a template char* or wchar_t* default function argument

binarybob0001 · 10-30-2009, 01:09 AM

I have a template similar to the following.

Code:

template <charT>
virtual void do_get_date(charT* = "str")
{ ... }

As you can see we have a problem. If we use a wchar_t instead the string wont be formatted right we need to prefix L in front. If we use char16_t we need to prefix a u in front. Is there a was to make the generic without resorting the the std::string class?

tuxdev · 10-30-2009, 01:31 AM

I'd suggest that you use plain old overloading here. There's no point in making it more generic than it actually needs to be.

Though, *why* do you want to do this? Most apps that actually bother to localize enforce the use of either UTF-8 std::string or std::wstring but not both. Mixing the two is a classic way to set yourself up to shooting yourself in the foot.

binarybob0001 · 10-30-2009, 01:46 AM

I just wanted to see if a general solution existed. I'm just reading over character sets and am trying to understand unicode. L must be a macro defined somewhere but I don't even know what it does. All attemps to find this macro using ctags have failed for me. I wonder if gcc just generates the macro. Maybe you could help. Unicode constists of 32 bits or a qword. Each qword contains a character of a place for character expansion (to my understanding). How does the formatting go. Say I wanted to type one of the Japanese alphabets. Which byte would contain what?