Description

Constexpr implementations of the functionality found in <cmath> and <cstdlib> proposed for C++23. In a constexpr context the functions will use an implementation defined in boost. If the context is not constexpr the functionality will be directly from the STL implementation of <cmath> used by the compiler. All functions that take an Integer type and return a double simply cast the Integer argument to a double. All of the following functions require C++17 or greater.

Synopsis

#include <boost/math/ccmath/ccmath.hpp>

namespace boost::math::ccmath {

    template <typename T>
    inline constexpr bool isinf(T x);

    template <typename T>
    inline constexpr bool isnan(T x);

    template <typename Real>
    inline constexpr Real sqrt(Real x);

    template <typename Integer>
    inline constexpr double sqrt(Integer x);

    template <typename T>
    inline constexpr T abs(T x);

    template <typename T, std::enable_if_t<std::is_unsigned_v<T>, bool> = true>
    inline constexpr int abs(T x);

    template <typename T>
    inline constexpr T fabs(T x);

    template <typename T>
    inline constexpr bool isfinite(T x);

    template <typename T>
    inline constexpr bool isnormal(T x);

    template <typename T>
    inline constexpr int fpclassify(T x);

    template <typename Real>
    inline constexpr Real frexp(Real arg, int* exp);

    template <typename Integer>
    inline constexpr double frexp(Integer arg, int* exp);

    template <typename Real>
    inline constexpr Real ldexp(Real arg, int exp);

    template <typename Integer>
    inline constexpr double ldexp(Integer arg, int exp);

    template <typename Integer>
    struct div_t {Integer quot; Integer rem;};

    template <typename Integer>
    inline constexpr div_t<Integer> div(Integer x, Integer y);

    template <typename Real>
    inline constexpr Real logb(Real arg);

    template <typename Integer>
    inline constexpr double logb(Integer arg);

    template <typename T>
    inline constexpr int ilogb(T arg);

    template <typename Real>
    inline constexpr Real scalbn(Real x, int exp) noexcept

    template <typename Integer>
    inline constexpr double scalbn(Integer x, int exp) noexcept

    template <typename Real>
    inline constexpr Real scalbln(Real x, long exp) noexcept

    template <typename Integer>
    inline constexpr double scalbln(Integer x, long exp) noexcept

    template <typename Real>
    inline constexpr Real floor(Real arg) noexcept

    template <typename Integer>
    inline constexpr double floor(Integer arg) noexcept

    template <typename Real>
    inline constexpr Real ceil(Real arg) noexcept

    template <typename Integer>
    inline constexpr double ceil(Integer arg) noexcept

    template <typename Real>
    inline constexpr Real trunc(Real arg) noexcept

    template <typename Integer>
    inline constexpr double trunc(Integer arg) noexcept

    template <typename Real>
    inline constexpr Real modf(Real x, Real* iptr) noexcept

    template <typename Real>
    inline constexpr Real round(Real arg) noexcept

    template <typename Integer>
    inline constexpr double round(Integer arg) noexcept

    template <typename T>
    inline constexpr long lround(T arg)

    template <typename T>
    inline constexpr long long llround(T arg)

    template <typename Real>
    inline constexpr Real fmod(Real x, Real y) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted fmod(Arithmetic1 x, Arithmetic2 y) noexcept
    The Promoted return type will have at least double prescision, but be up to the highest precision argument.

    template <typename Real>
    inline constexpr Real remainder(Real x, Real y) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted remainder(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Real>
    inline constexpr Real copysign(Real mag, Real sgn) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted copysign(Arithmetic1 mag, Arithmetic2 sgn) noexcept

    template <typename Real>
    inline constexpr Real hypot(Real x, Real y) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted hypot(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Real>
    inline constexpr Real fdim(Real x, Real y) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted fdim(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Real>
    inline constexpr Real fmax(Real x, Real y) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted fmax(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Real>
    inline constexpr Real fmin(Real x, Real y) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    inline constexpr Promoted fmin(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Arithmetic1, typename Arithmetic2 = Arithmetic1>
    inline constexpr bool isgreater(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Arithmetic1, typename Arithmetic2 = Arithmetic1>
    inline constexpr bool isgreaterequal(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Arithmetic1, typename Arithmetic2 = Arithmetic1>
    inline constexpr bool isless(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename Arithmetic1, typename Arithmetic2 = Arithmetic1>
    inline constexpr bool islessequal(Arithmetic1 x, Arithmetic2 y) noexcept

    template <typename T>
    inline constexpr bool isunordered(T x, T y) noexcept

    template <typename Real>
    inline constexpr Real fma(Real x, Real y, Real z) noexcept
    Requires compiling with fma flag

    template <typename Arithmetic1, typename Arithmetic2, typename Arithmetic3>
    inline constexpr Promoted fma(Arithmetic1 x, Arithmetic2 y, Arithmetic3 z) noexcept

    template <typename Arithmetic1, typename Arithmetic2>
    constexpr Promoted nextafter(Arithmetic1 from, Arithmetic2 to)

    template <typename T>
    constexpr Promoted nexttoward(T from, long double to)

    template <typename T>
    constexpr bool signbit(T arg)

} // Namespaces