#:include "common.fypp"
submodule(stdlib_math) stdlib_math_is_close
use, intrinsic :: ieee_arithmetic, only: ieee_is_nan
implicit none
#:for k1 in REAL_KINDS
real(${k1}$), parameter :: sqrt_eps_${k1}$ = sqrt(epsilon(1.0_${k1}$))
#:endfor
contains
#! Determines whether the values of `a` and `b` are close.
#:for k1, t1 in REAL_KINDS_TYPES
elemental module logical function is_close_${t1[0]}$${k1}$(a, b, rel_tol, abs_tol, equal_nan) result(close)
${t1}$, intent(in) :: a, b
real(${k1}$), intent(in), optional :: rel_tol, abs_tol
logical, intent(in), optional :: equal_nan
logical :: equal_nan_
equal_nan_ = optval(equal_nan, .false.)
if (ieee_is_nan(a) .or. ieee_is_nan(b)) then
close = merge(.true., .false., equal_nan_ .and. ieee_is_nan(a) .and. ieee_is_nan(b))
else
close = abs(a - b) <= max( abs(optval(rel_tol, sqrt_eps_${k1}$)*max(abs(a), abs(b))), &
abs(optval(abs_tol, 0.0_${k1}$)) )
end if
end function is_close_${t1[0]}$${k1}$
#:endfor
#:for k1, t1 in CMPLX_KINDS_TYPES
elemental module logical function is_close_${t1[0]}$${k1}$(a, b, rel_tol, abs_tol, equal_nan) result(close)
${t1}$, intent(in) :: a, b
real(${k1}$), intent(in), optional :: rel_tol, abs_tol
logical, intent(in), optional :: equal_nan
close = is_close_r${k1}$(a%re, b%re, rel_tol, abs_tol, equal_nan) .and. &
is_close_r${k1}$(a%im, b%im, rel_tol, abs_tol, equal_nan)
end function is_close_${t1[0]}$${k1}$
#:endfor
end submodule stdlib_math_is_close
