Tag Archive for: Visual Studio

TIL: About Visual Studio C++ and ‘for each in’

10 Mar
March 10, 2011

Most C++ developers are familiar using with for_each() when iterating over an STL collection. But a few months ago as I read a blogĀ post about the ‘auto’ keyword over at Marc Gregoire’s Blog I was dumbstruck when saw the following example:

[sourcecode language=”cpp”]
for each (auto m in myMap)
{
tcout << _T("Map element ") << m.first << _T(": ");
for each(auto e in m.second)
{
tcout << _T("'") << e << _T("', ");
}
tcout << endl;
}
[/sourcecode]

What the heck was this ‘for each’ without an underscore business? Apparently I’d been painfully unaware of this new syntax since 2004!!! It’s Microsoft/Visual Studio specific. But since my primary project is Windows-based through and through, you can bet I’ll be making use of this beauty to keep my code cleaner.

-CM12

PS. Do note, though, that this syntax automatically dereferences iterators, so it’s not useful if you need to do iterator manipulation.