int add int x int y short add short x short y float add float x float y double add double x double y string add string x string y T add T x T y return x + y ; template < typename T> = 使   add<int>(4,3); Add<double>(1.2598, 4.7653); add<string>("ABC", "DEF"); ( “T” )
STL = Standard Template Liblary Template     STL   vector list map INDEX     set INDEX ( )     stack LIFO queue 1 FIFO
STL v ector / list / map vector list map [0] [1] [2] [3] [4] [5] [0] [1] [2] [3] [4] [5] [ ] [ ] [ ] [ ] [ 椿 ] [ ] [6] [7] [6] [7] [8]
vector [0] [1] [2] [3] [4]
list