[vtk-developers] Updates to VTK's coding standard page

[David Thompson]

Hi Kyle,

>>> ... I don't understand why we insist upon the following:
>>> 
>>> * "[the STL] should be used sparingly"
>>> * "STL use should use the PIMPL idiom"
>>> * "When using anything declared in iostream, do not use std::"
> 
> I think you may have misinterpreted my post. I have no desire to
> change any of the VTK coding standards. I was merely curious as to the
> "why" behind some of them.

I cannot say that this accounts for *all* of the reasons for those guidelines, but:

1. The STL should be used sparingly.

  Compile times were (are?) noticeably higher when STL headers are included.

2. STL should be put in the private implementation.

  Same as above: by keeping STL out of header files, dependent classes do not incur compile-time overhead.

3. Do not use std:: for iostream.

  This is because of old MSVC compilers, some of which made cout, cerr, and some other iostream classes/instances available in the std namespace, some in the global namespace, and some attempted to make them available in both in a broken way.

	David