warn about xdp

Author: perazz

src/stdlib_linalg.fypp

@@ -251,7 +251,7 @@ module stdlib_linalg
     !!```
     !!     
     #:for rk,rt in RC_KINDS_TYPES
-    #:if rk!="xdp"
+    #:if rk!="xdp" ! BLAS/LAPACK backends do not currently support xdp
     module procedure stdlib_linalg_${rt[0]}$${rk}$determinant
     module procedure stdlib_linalg_pure_${rt[0]}$${rk}$determinant
     #:endif
@@ -280,15 +280,15 @@ module stdlib_linalg
     !!```
     !     
     #:for rk,rt in RC_KINDS_TYPES
-    #:if rk!="xdp"
+    #:if rk!="xdp" ! BLAS/LAPACK backends do not currently support xdp
     module procedure stdlib_linalg_pure_${rt[0]}$${rk}$determinant
     #:endif
     #:endfor        
   end interface operator(.det.)
 
   interface
     #:for rk,rt in RC_KINDS_TYPES
-    #:if rk!="xdp"
+    #:if rk!="xdp" ! BLAS/LAPACK backends do not currently support xdp
     module function stdlib_linalg_${rt[0]}$${rk}$determinant(a,overwrite_a,err) result(det)
         !> Input matrix a[m,n]
         ${rt}$, intent(inout), target :: a(:,:)

src/stdlib_linalg_determinant.fypp

@@ -14,7 +14,7 @@ submodule (stdlib_linalg) stdlib_linalg_determinant
      contains
 
      #:for rk,rt in RC_KINDS_TYPES
-     #:if rk!="xdp"
+     #:if rk!="xdp" ! BLAS/LAPACK backends do not currently support xdp
      module function stdlib_linalg_pure_${rt[0]}$${rk}$determinant(a) result(det)     
      !!### Summary
      !! Compute determinant of a real square matrix (pure interface).