Why would you do this? (I mean the standard unary functor). Thanks Andrew On Wed, Dec 9, 2009 at 11:10 AM, Peter Dimov <pdimov@pdimov.com> wrote:
Vadim Guchenko wrote:
Hello, All!
Is there a simple way to create a functor that returns one of its arguments _1, _2, ...? Does standard unary functor exist, which simply returns its argument unchanged? I.e.:
template<typename T> struct arg: public std::unary_function<T, T> { T operator()(const T &x) const { return x; } };
It's not part of the current standard, but many implementations provide std::identity as an extension. (It will be standard in C++0x.) _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users
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