Add assert_always subroutine

This procedure is similar to assert, but enforcement is unconditionally enabled
(ignores the `ASSERTIONS` define).

Potentially useful in callers where performance is not a concern but
correctness checking is critical.

Currently undocumented.

Author: bonachea

src/assert/assert_subroutine_m.F90

@@ -33,7 +33,7 @@ module assert_subroutine_m
   !!
   implicit none
   private
-  public :: assert
+  public :: assert, assert_always
 
 #ifndef USE_ASSERTIONS
 #  if ASSERTIONS
@@ -47,7 +47,8 @@ module assert_subroutine_m
   interface
 
     pure module subroutine assert(assertion, description, diagnostic_data)
-      !! If assertion is .false., error-terminate with a character stop code that contains diagnostic_data if present
+      !! If assertion is .false. and enforcement is enabled (e.g. via -DASSERTIONS=1), 
+      !! then error-terminate with a character stop code that contains diagnostic_data if present
       implicit none
       logical, intent(in) :: assertion
         !! Most assertions will be expressions such as i>0
@@ -57,6 +58,14 @@ pure module subroutine assert(assertion, description, diagnostic_data)
         !! Data to include in an error ouptput: may be of an intrinsic type or a type that extends characterizable_t
     end subroutine
 
+    pure module subroutine assert_always(assertion, description, diagnostic_data)
+      !! Same as above but always enforces the assertion (regardless of ASSERTIONS)
+      implicit none
+      logical, intent(in) :: assertion
+      character(len=*), intent(in) :: description
+      class(*), intent(in), optional :: diagnostic_data
+    end subroutine
+
   end interface
 
 end module assert_subroutine_m

src/assert/assert_subroutine_s.F90

@@ -10,12 +10,18 @@
 contains
 
   module procedure assert
-    use characterizable_m, only : characterizable_t
-
-    character(len=:), allocatable :: header, trailer
 
     toggle_assertions: &
     if (enforce_assertions) then
+        call assert_always(assertion, description, diagnostic_data)
+    end if toggle_assertions
+    
+  end procedure
+
+  module procedure assert_always
+    use characterizable_m, only : characterizable_t
+
+    character(len=:), allocatable :: header, trailer
 
       check_assertion: &
       if (.not. assertion) then
@@ -59,8 +65,6 @@
 
       end if check_assertion
 
-    end if toggle_assertions
-    
   contains
 
     pure function string(numeric) result(number_as_string)