Boost C++ Libraries: Ticket #1900: Missing documentation for mpl::print in the MPL library

component changed; owner set

Marshall Clow — Wed, 21 May 2008 14:53:13 GMT

owner set to Douglas Gregor
component None → mpi

owner, component changed

Douglas Gregor — Wed, 21 May 2008 17:33:09 GMT

owner changed from Douglas Gregor to Aleksey Gurtovoy
component mpi → mpl

owner changed

Mathias Gaunard — Fri, 08 Jul 2011 07:56:38 GMT

owner changed from Aleksey Gurtovoy to Joel Falcou

There is also a test but it doesn't appear to be compiled.

It would be nice if it were possible to test a warning is indeed emitted.

Robert Ramey — Sun, 27 Nov 2011 17:33:58 GMT

Comment:

I find mpl print indispensable. However the following should be noted somewhere:

a) in order to work with GCC -Wall (or likely some more specific warning) must be set in the command line. Actually I should be -Wsign-compare. This is the case with gcc-4.5.3

b) The following only prints the first time

struct a; typedef a b;

mpl::print<a> this displays mpl::print<a> this doesn't display mpl::print<b> neither does this.

I don't think this can be actually fixed, but I would be nice to see it noted in the manual.

Robert Ramey

Mathias Gaunard — Sun, 27 Nov 2011 18:46:09 GMT

There are better tricks for displaying types with GCC.

I personally just use

template<class T>
struct print
{
  unsigned : 80;
  typedef T type;
};

doesn't work at all with other compilers though.