[ratio.arithmetic]

If it is not possible to represent U or V with intmax_t, the program is ill-formed.

Otherwise, an implementation should yield correct values of U and V.

If it is not possible to represent X or Y with intmax_t, the program is ill-formed unless the implementation yields correct values of U and V.

Table 65 — Expressions used to perform ratio arithmetic [tab:ratio.arithmetic]

🔗 Type	Value of X	Value of Y
🔗 ratio_add<R1, R2>	R1::num * R2::den +	R1::den * R2::den
🔗	R2::num * R1::den
🔗 ratio_subtract<R1, R2>	R1::num * R2::den -	R1::den * R2::den
🔗	R2::num * R1::den
🔗 ratio_multiply<R1, R2>	R1::num * R2::num	R1::den * R2::den
🔗 ratio_divide<R1, R2>	R1::num * R2::den	R1::den * R2::num

[Example 1: static_assert(ratio_add<ratio<1, 3>, ratio<1, 6>::num == 1, "1/3+1/6 == 1/2"); static_assert(ratio_add<ratio<1, 3>, ratio<1, 6>::den == 2, "1/3+1/6 == 1/2"); static_assert(ratio_multiply<ratio<1, 3>, ratio<3, 2>::num == 1, "1/3*3/2 == 1/2"); static_assert(ratio_multiply<ratio<1, 3>, ratio<3, 2>::den == 2, "1/3*3/2 == 1/2"); / The following cases may cause the program to be ill-formed under some implementations static_assert(ratio_add<ratio<1, INT_MAX>, ratio<1, INT_MAX>>::num == 2, "1/MAX+1/MAX == 2/MAX"); static_assert(ratio_add<ratio<1, INT_MAX>, ratio<1, INT_MAX>>::den == INT_MAX, "1/MAX+1/MAX == 2/MAX"); static_assert(ratio_multiply<ratio<1, INT_MAX>, ratio<INT_MAX, 2>::num == 1, "1/MAX * MAX/2 == 1/2"); static_assert(ratio_multiply<ratio<1, INT_MAX>, ratio<INT_MAX, 2>::den == 2, "1/MAX * MAX/2 == 1/2"); — end example]