C++ Reference: Standard C++ Library reference: C Library: ctime

C++官网参考链接：https://cplusplus.com/reference/ctime/

头文件 
(time.h)
C时间库
此头文件包含用于获取和操作日期和时间信息的函数定义。 
函数
时间操作 
clock    Clock program (function)
difftime    Return difference between two times (function)
mktime    Convert tm structure to time_t (function)
time    Get current time (function)

转换 
asctime    Convert tm structure to string (function)
ctime    Convert time_t value to string (function)
gmtime    Convert time_t to tm as UTC time (function)
localtime    Convert time_t to tm as local time (function)
strftime    Format time as string (function)

宏常量 
CLOCKS_PER_SEC    Clock ticks per second (macro)
NULL    Null pointer (macro)

类型
clock_t    Clock type (type)
size_t    Unsigned integral type (type)
time_t    Time type (type)
struct tm    Time structure (type)