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Standard library header <ratio> (C++11)

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C++
Standard library headers

此头文件是 编译时有理数算术 库的组成部分。

目录

类

(C++11)
表示精确有理分数
(类模板)
算术运算
(C++11)
在编译时相加两个 ratio 对象
(别名模板)
(C++11)
在编译时相减两个 ratio 对象
(别名模板)
(C++11)
在编译时相乘两个 ratio 对象
(别名模板)
(C++11)
在编译时相除两个 ratio 对象
(别名模板)
比较运算
(C++11)
在编译时比较两个 ratio 对象是否相等
(类模板)
(C++11)
在编译时比较两个 ratio 对象是否不相等
(类模板)
(C++11)
在编译时比较两个 ratio 对象是否满足 小于 关系
(类模板)
(C++11)
在编译时比较两个 ratio 对象是否满足 小于等于 关系
(类模板)
(C++11)
在编译时比较两个 ratio 对象是否满足 大于 关系
(类模板)
(C++11)
在编译时比较两个 ratio 对象是否满足 大于等于 关系
(类模板)
类型别名
quecto (C++26) std:: ratio < 1 , 1000000000000000000000000000000 > ，若 std::intmax_t 能表示分母
ronto (C++26) std:: ratio < 1 , 1000000000000000000000000000 > ，若 std::intmax_t 能表示分母
yocto std:: ratio < 1 , 1000000000000000000000000 > ，若 std::intmax_t 能表示分母
zepto std:: ratio < 1 , 1000000000000000000000 > ，若 std::intmax_t 能表示分母
atto std:: ratio < 1 , 1000000000000000000 >
femto std:: ratio < 1 , 1000000000000000 >
pico std:: ratio < 1 , 1000000000000 >
nano std:: ratio < 1 , 1000000000 >
micro std:: ratio < 1 , 1000000 >
milli std:: ratio < 1 , 1000 >
centi std:: ratio < 1 , 100 >
deci std:: ratio < 1 , 10 >
deca std:: ratio < 10 , 1 >
hecto std:: ratio < 100 , 1 >
kilo std:: ratio < 1000 , 1 >
mega std:: ratio < 1000000 , 1 >
giga std:: ratio < 1000000000 , 1 >
tera std:: ratio < 1000000000000 , 1 >
peta std:: ratio < 1000000000000000 , 1 >
exa std:: ratio < 1000000000000000000 , 1 >
zetta std:: ratio < 1000000000000000000000 , 1 > ，若 std::intmax_t 能表示分子
yotta std:: ratio < 1000000000000000000000000 , 1 > ，若 std::intmax_t 能表示分子
ronna (C++26) std:: ratio < 1000000000000000000000000000 , 1 > ，若 std::intmax_t 能表示分子
quetta (C++26) std:: ratio < 1000000000000000000000000000000 , 1 > ，若 std::intmax_t 能表示分子

概要 

namespace std {
    // 类模板 ratio
    template <intmax_t N, intmax_t D = 1>
    class ratio {
    public:
        typedef ratio<num, den> type;
        static constexpr intmax_t num;
        static constexpr intmax_t den;
    };
    // ratio 算术运算
    template <class R1, class   R2> using   ratio_add      = /*ratio*/;
    template <class R1, class   R2> using   ratio_subtract = /*ratio*/;
    template <class R1, class   R2> using   ratio_multiply = /*ratio*/;
    template <class R1, class   R2> using   ratio_divide   = /*ratio*/;
    // ratio 比较运算
    template <class R1, class R2> struct ratio_equal;
    template <class R1, class R2> struct ratio_not_equal;
    template <class R1, class R2> struct ratio_less;
    template <class R1, class R2> struct ratio_less_equal;
    template <class R1, class R2> struct ratio_greater;
    template <class R1, class R2> struct ratio_greater_equal;
    // 常用 SI 单位类型定义
    typedef ratio<1, 1000000000000000000000000000000> quecto;
    typedef ratio<1,    1000000000000000000000000000> ronto;
    typedef ratio<1,       1000000000000000000000000> yocto;
    typedef ratio<1,          1000000000000000000000> zepto;
    typedef ratio<1,             1000000000000000000> atto;
    typedef ratio<1,                1000000000000000> femto;
    typedef ratio<1,                   1000000000000> pico;
    typedef ratio<1,                      1000000000> nano;
    typedef ratio<1,                         1000000> micro;
    typedef ratio<1,                            1000> milli;
    typedef ratio<1,                             100> centi;
    typedef ratio<1,                              10> deci;
    typedef ratio<                             10, 1> deca;
    typedef ratio<                            100, 1> hecto;
    typedef ratio<                           1000, 1> kilo;
    typedef ratio<                        1000000, 1> mega;
    typedef ratio<                     1000000000, 1> giga;
    typedef ratio<                  1000000000000, 1> tera;
    typedef ratio<               1000000000000000, 1> peta;
    typedef ratio<            1000000000000000000, 1> exa;
    typedef ratio<         1000000000000000000000, 1> zetta;
    typedef ratio<      1000000000000000000000000, 1> yotta;
    typedef ratio<   1000000000000000000000000000, 1> ronna;
    typedef ratio<1000000000000000000000000000000, 1> quetta;
}