Den 31-01-2012 21:37, Ion Gaztañaga skrev:
El 31/01/2012 14:47, Stephan T. Lavavej escribió:
[Thorsten Ottosen]
Although returning vectors by value might be a good idea for factories, and such things, it's always more efficient to pass a reference to a vector, and clear() + fill or assign, or even better, reusing already constructed values (which can be vectors of vectors). Using filesystem::path in a loop might trigger a lot of allocations that could be avoided if the string could be passed as an argument, reusing already allocated memory for each path.
In my case "glob" performance is not important; STLSofts version is probabily much faster. Remark 1: with the &/&& syntax of C++11, at least the temporary strings are more efficient, as we can move the value. Remark 2: The fact that functions like extension() returns a temporary path object seems overkill (I know its only a cheap string copy, but still). I fail to see how ".foo" can be a path. I feel that the problem is that there is no uniform handling of strings in the interface/internally. If the path objects stored/acccepted utf8 strings, we would have a very nice, clean interface. Taking extension() as an example, we have the following options: A. return a temporary path B. return a temporary string C. add a function, path::has_extention( const std::string& ); D. add a free function, has_extension( const path& p, const string& ); I think the latter are to be preferred, and I don't think there is any overhead at all with them. -Thorsten