mattsan / bitoperation Goto Github PK

bits operating classes
written by MATSUMOTO Eiji
from March 2, 2010

0. Basis

    include file : Bits.h
    namespace    : emattsan::bits

1. Integer types of specified number of bits

    Bits<4, signed> s; // signed 4 bit integer (-8..7)
    Bits<4>         u; // (or Bits<4, unsigned>) unsigned 4 bit integer (0..15)

    s = 7;  // s => 7
    s = 8;  // s => -8
    s = 15; // s => -1
    s = 16; // s => 0

    u = 7;  // u => 7
    u = 8;  // u => 8
    u = 15; // u => 15
    u = 16; // u => 0

2. Join

    Bits<4, signed> s(1); // s => 1 ( 0001b )
    BIts<4>         u(8); // u => 8 ( 1000b )

    int n = (s, u); // n => 24 ( 18h / 00011000b )

    int n = (s, s, s); // n => 265 ( 111h / 000100010001b )

    (s, n) = 0x5a; // s => 5, n = 10 ( 0ah )

3. Reserved bits

    Bits<4, signed> s(1); // s => 1 ( 0001b )
    Bits<4>         u(8); // u => 8 ( 1000b )

    int n = (s, reserve<2>, u); // n => 72 ( 048h / 0001001000b )

    (s, reserve<2>, u) = 0xff; // s => 3 ( 0011b), (2 reserved bits discarded), u => 15 ( 1111b ), 


<<EOF>>