sort_index: add fypp variable to reduce code size

Author: jvdp1

src/stdlib_sorting.fypp

@@ -435,40 +435,24 @@ module stdlib_sorting
 !! with a value of `.TRUE.` the indices correspond to a non-increasing sort.
 
 #:for k1 in INT_KINDS
+#:for k1, t1 in IR_KINDS_TYPES
         module subroutine ${k1}$_sort_index( array, index, work, iwork, &
             reverse )
 !! Version: experimental
 !!
-!! `${k1}$_sort_index( array )` sorts an input `ARRAY` of type `INTEGER(${k1}$)`
+!! `${k1}$_sort_index( array )` sorts an input `ARRAY` of type `${t1}$`
 !! using a hybrid sort based on the `'Rust" sort` algorithm found in `slice.rs`
 !! and returns the sorted `ARRAY` and an array `INDEX of indices in the
 !! order that would sort the input `ARRAY` in the desired direction.
-            integer(${k1}$), intent(inout)             :: array(0:)
+            ${t1}$, intent(inout)                      :: array(0:)
             integer(int_size), intent(inout)           :: index(0:)
-            integer(${k1}$), intent(inout), optional   :: work(0:)
+            ${t1}$, intent(inout), optional            :: work(0:)
             integer(int_size), intent(inout), optional :: iwork(0:)
             logical, intent(in), optional              :: reverse
         end subroutine ${k1}$_sort_index
 
 #:endfor
 
-#:for k1 in REAL_KINDS
-        module subroutine ${k1}$_sort_index( array, index, work, iwork, &
-            reverse )
-!! Version: experimental
-!!
-!! `${k1}$_sort_index( array )` sorts an input `ARRAY` of type `REAL(${k1}$)`
-!! using a hybrid sort based on the `'Rust" sort` algorithm found in `slice.rs`
-!! and returns the sorted `ARRAY` and an array `INDEX of indices in the
-!! order that would sort the input `ARRAY` in the desired direction.
-            real(${k1}$), intent(inout)                :: array(0:)
-            integer(int_size), intent(inout)           :: index(0:)
-            real(${k1}$), intent(inout), optional      :: work(0:)
-            integer(int_size), intent(inout), optional :: iwork(0:)
-            logical, intent(in), optional              :: reverse
-        end subroutine ${k1}$_sort_index
-
-#:endfor
         module subroutine char_sort_index( array, index, work, iwork, &
             reverse )
 !! Version: experimental