From fb51e3c4cd45372b394f5963c88063472a3a776a Mon Sep 17 00:00:00 2001
From: Martin Diehl <mail@martin-diehl.net>
Date: Wed, 29 Dec 2021 07:19:26 +0100
Subject: [PATCH] functions have no side-effects, hence 'pure'

---
 src/lattice.f90 |  4 ++--
 src/math.f90    | 12 ++++++------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/lattice.f90 b/src/lattice.f90
index 50d4b6c51..3089aa30b 100644
--- a/src/lattice.f90
+++ b/src/lattice.f90
@@ -2070,7 +2070,7 @@ end function getlabels
 !> @brief Equivalent Poisson's ratio (ν)
 !> @details https://doi.org/10.1143/JPSJ.20.635
 !--------------------------------------------------------------------------------------------------
-function lattice_equivalent_nu(C,assumption) result(nu)
+pure function lattice_equivalent_nu(C,assumption) result(nu)
 
   real(pReal), dimension(6,6), intent(in) :: C                                                      !< Stiffness tensor (Voigt notation)
   character(len=5),            intent(in) :: assumption                                             !< Assumption ('Voigt' = isostrain, 'Reuss' = isostress)
@@ -2103,7 +2103,7 @@ end function lattice_equivalent_nu
 !> @brief Equivalent shear modulus (μ)
 !> @details https://doi.org/10.1143/JPSJ.20.635
 !--------------------------------------------------------------------------------------------------
-function lattice_equivalent_mu(C,assumption) result(mu)
+pure function lattice_equivalent_mu(C,assumption) result(mu)
 
   real(pReal), dimension(6,6), intent(in) :: C                                                      !< Stiffness tensor (Voigt notation)
   character(len=5),            intent(in) :: assumption                                             !< Assumption ('Voigt' = isostrain, 'Reuss' = isostress)
diff --git a/src/math.f90 b/src/math.f90
index 2d8f8fb3b..34cb6eecb 100644
--- a/src/math.f90
+++ b/src/math.f90
@@ -512,7 +512,7 @@ end subroutine math_invert33
 !--------------------------------------------------------------------------------------------------
 !> @brief Inversion of symmetriced 3x3x3x3 matrix
 !--------------------------------------------------------------------------------------------------
-function math_invSym3333(A)
+pure function math_invSym3333(A)
 
   real(pReal),dimension(3,3,3,3)            :: math_invSym3333
 
@@ -538,7 +538,7 @@ end function math_invSym3333
 !--------------------------------------------------------------------------------------------------
 !> @brief invert quadratic matrix of arbitrary dimension
 !--------------------------------------------------------------------------------------------------
-subroutine math_invert(InvA, error, A)
+pure subroutine math_invert(InvA, error, A)
 
   real(pReal), dimension(:,:),                 intent(in)  :: A
   real(pReal), dimension(size(A,1),size(A,1)), intent(out) :: invA
@@ -996,7 +996,7 @@ end subroutine math_normal
 !--------------------------------------------------------------------------------------------------
 !> @brief eigenvalues and eigenvectors of symmetric matrix
 !--------------------------------------------------------------------------------------------------
-subroutine math_eigh(w,v,error,m)
+pure subroutine math_eigh(w,v,error,m)
 
   real(pReal), dimension(:,:),                  intent(in)  :: m                                    !< quadratic matrix to compute eigenvectors and values of
   real(pReal), dimension(size(m,1)),            intent(out) :: w                                    !< eigenvalues
@@ -1021,7 +1021,7 @@ end subroutine math_eigh
 !> @author Martin Diehl, Max-Planck-Institut für Eisenforschung GmbH
 !> @details See http://arxiv.org/abs/physics/0610206 (DSYEVH3)
 !--------------------------------------------------------------------------------------------------
-subroutine math_eigh33(w,v,m)
+pure subroutine math_eigh33(w,v,m)
 
   real(pReal), dimension(3,3),intent(in)  :: m                                                      !< 3x3 matrix to compute eigenvectors and values of
   real(pReal), dimension(3),  intent(out) :: w                                                      !< eigenvalues
@@ -1114,7 +1114,7 @@ end function math_rotationalPart
 !> @brief Eigenvalues of symmetric matrix
 ! will return NaN on error
 !--------------------------------------------------------------------------------------------------
-function math_eigvalsh(m)
+pure function math_eigvalsh(m)
 
   real(pReal), dimension(:,:),                  intent(in)  :: m                                    !< symmetric matrix to compute eigenvalues of
   real(pReal), dimension(size(m,1))                         :: math_eigvalsh
@@ -1137,7 +1137,7 @@ end function math_eigvalsh
 !> but apparently more stable solution and has general LAPACK powered version for arbritrary sized
 !> matrices as fallback
 !--------------------------------------------------------------------------------------------------
-function math_eigvalsh33(m)
+pure function math_eigvalsh33(m)
 
   real(pReal), intent(in), dimension(3,3) :: m                                                      !< 3x3 symmetric matrix to compute eigenvalues of
   real(pReal), dimension(3) :: math_eigvalsh33,I