Beman Dawes wrote:
On Wed, Oct 29, 2008 at 11:33 PM, Edward Diener <eldiener@tropicsoft.com>wrote:
Beman Dawes wrote: ... The issue for me was just ease of instantiation of a basic_path based solely on a string type ( which is actually a character type ). One can not currently instantiate a basic_path with:
boost::filesystem::basic_path<std::basic_string<char>, boost::filesystem::basic_trait<std::basic_string<char> > > myPath;
where one just specifies the character type.
Why would one want to do that ? For two reasons:
1) In a VC++ program which may be multibyte or Unicode depending on a compiler option, we would have:
boost::filesystem::basic_path<std::basic_string<_TCHAR>, boost::filesystem::basic_trait<std::basic_string<_TCHAR> > > myPath;
2) A template class or template function taking a character type parameter would just pass that type in to filesystem to instantiate the correct type path.
So I do not know whether your version 3 solves makes that easier or not, but hopefully it does.
Here is an example; this code does compile and run correctly under V3:
#include <boost/filesystem/path.hpp> #include <boost/filesystem/operations.hpp> #include <string> #include <cassert> #include <windows.h> #include <winnt.h>
namespace fs = boost::filesystem;
typedef std::basic_string<TCHAR> tstring;
void func( const fs::path & p ) { assert( fs::exists( p ) ); }
int main() { // get a path that is known to exist fs::path cp = fs::current_path();
// demo: get tstring from the path tstring cp_as_tstring = cp.string<tstring>();
// demo: pass tstring to filesystem function taking path assert( fs::exists( cp_as_tstring ) );
// demo: pass tstring to user function taking path func( cp_as_tstring );
return 0; }
It looks like you are saying that a boost::filesystem::path can be created from any string type and that one can retrieve the path as any string type. I can not think of any immediate objection to using boost::filesystem::path in this way, and it does simplify the use of it with different string types. This certainly seems like a worthwhile way to upgrade the library.