carter的专栏

// Structure Size example#include struct A { char a; long b; char c; long d; } ;struct B { char a; char c; long b; long d; } ;#pragma pack(push,1)struct C { char a; long b; ch

整型在除法是要做转换，在其他运算中有明显的速度优势

// Table definition:typedef long (*functs)(char c);functs JumpTable[] = { DoOne,DoTwo,DoThree /* etc*/} ;// some code that uses the table:long result = JumpTable[selector](i++);转移表的内在的基本思路在于：将待调用函数的

struct BitField{    unsigned rangeAOne     : 11;    // long 1;    unsigned rangeATwo     : 11;    unsigned rangeBOne     : 10;    unsigned rangeAThree   : 11;    // long 2;    unsigned rangeAFour    :