void foo()
А>{
А>    int a = 5;
А>    {
А>        int a;
А>        a = 3;
А>    }
А>    printf( "%d\n", a ); // выдаст естественно "5"
А>}

C:\temp>cl test.cpp /analyze
Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 15.00.30729.01 for 80x86
Copyright (C) Microsoft Corporation. All rights reserved.

test.cpp
c:\temp\test.cpp(6) : warning C6246: Local declaration of 'a' hides declaration of the same name in outer scope. For addition al information, see previous declaration at line '4' of 'c:\temp\test.cpp': Lines: 4