On Wed, 26 Oct 2005, Joshua Schpok wrote:
I want to make a 3D array of std::lists:
boost::multi_array<std::list<CSomething>,3> listbin;
Then I'd like to actually use those lists:
/// Walk through list at x,y,z for(std::list<CSomething>::iterator iter = listbin[x][y][z].begin(); reti != iter[x][y][z].end(); iter++) { iter->m_foo += 42; }
But multi_array is giving me back *const* list iterators, producing the error:
error: conversion from `std::_List_const_iterator<CSomething>' to non-scalar type `std::_List_iterator<CSomething>' requested
Why is this so? I can trick the compiler by doing a cast like:
Seems like your variable listbin is const itself (or a const reference). Boost.MultiArray's operator[] is overloaded for const, so if your listbin is not const, it should not be a problem.
std::list<CSomething>::iterator iter = ((std::list<CSomething>)listbin[x][y][z]).begin();
but this seems to poop out at runtime.
Of course, you are making a copy of your list through this cast! And then you take an iterator to a temporary object. When you dereference that iterator: boom!
Is there a proper way to do this?
Make sure listbin is not const! -- Francois