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Function `core.bitop.bsr`

Scans the bits in v from the most significant bit to the least significant bit, looking for the first set bit.


						
				int bsr
				(
				

				  uint v
				

				) pure nothrow @nogc @safe;
				

				

				int bsr
				(
				

				  ulong v
				

				) pure nothrow @nogc @safe;

Returns

The bit number of the first bit set. The return value is undefined if v is zero.

Example

writeln(bsr(0x21)); // 5
writeln(bsr((ulong.max >> 15) - 1)); // 48

Authors

Don Clugston, Sean Kelly, Walter Bright, Alex Rønne Petersen, Thomas Stuart Bockman

License

Boost License 1.0