[Nicolai, if you disagree with the analysis below, please let us know]
Sean Perry <[EMAIL PROTECTED]> writes:
> the code below is from Josuttis' "The C++ standard library" and I
> have seen it elsewhere. It works under 2.95.4.
AFAICT, the code is incorrect.
> int main(int argc, char* argv[]) {
> string foo = "Some Mixed Case Text";
> cout << foo << endl;
> transform(foo.begin(), foo.end(), foo.begin(), tolower);
The compiler can't properly resolve "tolower": The problem is that
tolower is not only a function in namespace std, it is also a template
(22.1.3/2). Therefore, in the call to transform, template argument
deduction fails because of the ambiguity.
You can fix your code in the following ways:
1. Define a wrapper function around tolower that you pass to
transform.
2. Explicitly select the tolower you want to use, by writing
transform(foo.begin(), foo.end(), foo.begin(), (int(*)(int))std::tolower);
The cast causes, on the one hand, an explicit overload resolution
in favour of the function; it also allows the compiler to properly
deduce the third argument to transform.
Regards,
Martin
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