Programming languages such as Python, Ruby and the latest version of Java support binary literals. Binary literals are useful for domains that operate a lot on the bit-level.

It is provided as a compiler extension to C++ in the GCC and Digital Mars compilers and for usefulness and to aid portability I think VC++ should have them too.

Integer constants can be written as binary constants, consisting of a sequence of `0' and `1' digits, prefixed by `0b' or `0B'.

For example:
int i = 0b011101010;

The type of these constants follows the same rules as for octal or hexadecimal integer constants, so suffixes like `L' or `UL' can be applied.

If binary literals were implemented it would be useful for the iostreams to have a binary manipulator like dec, hex and oct currently. A "%b" format specifier for the printf/sprintf family would also be very useful. Otherwise, everybody will be rolling their own binary to string conversion functions and classes for this.

As an alternative we could use std::bitset. For example:
const int mybin = std::bitset<32>("10101101").to_ulong()
However, using this method is non-idiomatic and inefficient as the string has to be parsed at runtime.

I am aware that C++0x provides user-defined literals but these are inconvenient as the user has to define their own binary conversion function. Also, everybody will roll their own incompatible binary literals.