A neat trick. "a"[0] = 'k'; As you suspected, GCC catches the problem during compilation. MSDEV, on the other hand will not catch it if you compile as cl test.c If you create a project, and if /ZI is one of the compile time options, then MSDEV allows you to compile/link - but if you run it - you get a run time exception. Try compiling as: cl /ZI test.c BTW I am using vc7 from Visual Studio .Net 2003. "Back then memory was scarce" - it still is. Just depends upon what are programming. If you are programming a toy to be sold for pennies - then you wish like hell you had a byte more.