search for: select1st

I've run into a use case where I'd like to use a mapped_iterator to iterator the 1st (or 2nd) items in a sequence of std::pairs. Does select1st/select2nd exist somewhere within LLVM or is there some equivalent? If not, I'll add it. -Dave

I believe he's referring to this: http://www.sgi.com/tech/stl/select1st.html On Fri, Jul 15, 2011 at 1:29 PM, Chris Lattner <clattner at apple.com> wrote: > > On Jul 15, 2011, at 12:35 PM, David Greene wrote: > >> I've run into a use case where I'd like to use a mapped_iterator to >> iterator the 1st (or 2nd) items in a sequence of s...

On Jul 15, 2011, at 12:35 PM, David Greene wrote: > I've run into a use case where I'd like to use a mapped_iterator to > iterator the 1st (or 2nd) items in a sequence of std::pairs. Does > select1st/select2nd exist somewhere within LLVM or is there some > equivalent? If not, I'll add it. Is this making the resultant loop simpler? C++ without lambda's isn't very friendly to functors, what is the before/after effect of doing this? -Chris

Chris Lattner <clattner at apple.com> writes: > On Jul 15, 2011, at 12:35 PM, David Greene wrote: > >> I've run into a use case where I'd like to use a mapped_iterator to >> iterator the 1st (or 2nd) items in a sequence of std::pairs. Does >> select1st/select2nd exist somewhere within LLVM or is there some >> equivalent? If not, I'll add it. > > Is this making the resultant loop simpler? C++ without lambda's isn't > very friendly to functors, what is the before/after effect of doing > this? It's going to unify...

Chris Lattner <clattner at apple.com> writes: > The problem that I have with this sort of higher order metaprogramming Metaprogramming? This isn't template metaprogramming if that's what you mean. > in C++'98 is that you're trading one set of complexity for another. What's the other complexity? -Dave

I'm talking about mapped iterator + select1st. -Chris On Jul 16, 2011, at 2:58 PM, greened at obbligato.org (David A. Greene) wrote: > Chris Lattner <clattner at apple.com> writes: > >> The problem that I have with this sort of higher order metaprogramming > > Metaprogramming? This isn't template metaprogrammi...

...tner <clattner at apple.com> writes: > >> On Jul 15, 2011, at 12:35 PM, David Greene wrote: >> >>> I've run into a use case where I'd like to use a mapped_iterator to >>> iterator the 1st (or 2nd) items in a sequence of std::pairs. Does >>> select1st/select2nd exist somewhere within LLVM or is there some >>> equivalent? If not, I'll add it. >> >> Is this making the resultant loop simpler? C++ without lambda's isn't >> very friendly to functors, what is the before/after effect of doing >> this? &gt...