Templates and wchar_t

[michaelwilliams6511]

I do not understand why I am getting the error "no instance of overload function "remove" matches the argument list. I am trying to pass a wchar_t and a const wchar_t. My project is set to use c++ 17 in VS2019. I am trying to follow along with a text reference (Modern C++ Cookbook). From what I have read, CharT should just be a placeholder to a string, wstring, etc. so I am not sure why I am getting this error.

Here is my templated function (directly from the text)

  template<typename CharT>
using tstring = std::basic_string<CharT, std::char_traits<CharT>, std::allocator<CharT>>;
template<typename CharT>
inline tstring<CharT> remove(tstring<CharT> text, CharT const ch)
{
	auto start = std::remove_if(std::begin(text), std::end(text), [=](CharT const c)
		{
			return c == ch;
		});
	text.erase(start, std::end(text));
	return text;
}

And then how I am trying to call it from main:

	std::wstring testString = L"This is a test string!";
        auto removeCharString{ remove(testString, L"!")};

[Niccolo]

auto removeCharString{ remove(testString, L'!')};

Putting "!" in quotes makes it a string, whereas putting it in single quotes makes it a character.

Also, it's a tough thing for VS2019 to handle (the compiler make choke). I had to use Clang to compile this to get error information (was getting a crash of cl.exe, typical of Microsoft).

The error was a bit cryptic, where this alternate formation made it easier in Microsoft

auto removeCharString = remove( testString, L'!');

Though I understand why you'd prefer the former - clang was better at reporting the nature of the problem.

If you aren't using clang, I can recommend (highly) that you modify the VS2019 install to use clang. I have to hand it to Microsoft, that in VS2019 and VS2017, clang installation and usage is about the best it can be on Windows.

It take a few tries to figure out how to set the project to use Clang. I personally create configurations of Debug/Release/ClangDebug/ClangRelease, setting the tool set for clang in the latter two.

It really does help a lot to use clang.

However, I don't suggest copying a configuration from a Microsoft configured configuration, then change it to clang. It gets confused, but fixes itself if you close and re-open the project. It seems that if you change toolsets on a existing project configuration (that you've changed any settings on), VS attempts to assign Microsoft compiler project settings to clang, which doesn't work (lots of complaints). Close and re-open the project seems to cause the IDE to re-evaluate and correct it.

[michaelwilliams6511]

Thanks, that did the trick. Will look into integrating clang into my setup. Appreciate the help and the quick response.