[PATCH] c++: document comp_template_args's default args

[Jason Merrill]

On 5/27/22 14:07, Patrick Palka wrote:
> In passing, use bool for its return type.

OK.

> gcc/cp/ChangeLog:
> 
> 	* cp-tree.h (comp_template_args): Change return type to bool.
> 	* pt.cc (comp_template_args): Document default arguments.
> 	Change return type to bool and adjust returns accordingly.
> ---
>   gcc/cp/cp-tree.h |  2 +-
>   gcc/cp/pt.cc     | 24 +++++++++++-------------
>   2 files changed, 12 insertions(+), 14 deletions(-)
> 
> diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
> index d77fd1eb8a9..da8898155e0 100644
> --- a/gcc/cp/cp-tree.h
> +++ b/gcc/cp/cp-tree.h
> @@ -7327,7 +7327,7 @@ extern tree get_template_info			(const_tree);
>   extern int template_class_depth			(tree);
>   extern int is_specialization_of			(tree, tree);
>   extern bool is_specialization_of_friend		(tree, tree);
> -extern int comp_template_args			(tree, tree, tree * = NULL,
> +extern bool comp_template_args			(tree, tree, tree * = NULL,
>   						 tree * = NULL, bool = false);
>   extern int template_args_equal                  (tree, tree, bool = false);
>   extern tree maybe_process_partial_specialization (tree);
> diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
> index ec168234325..b5064990857 100644
> --- a/gcc/cp/pt.cc
> +++ b/gcc/cp/pt.cc
> @@ -9368,27 +9368,25 @@ template_args_equal (tree ot, tree nt, bool partial_order /* = false */)
>       }
>   }
>   
> -/* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
> -   template arguments.  Returns 0 otherwise, and updates OLDARG_PTR and
> +/* Returns true iff the OLDARGS and NEWARGS are in fact identical sets of
> +   template arguments.  Returns false otherwise, and updates OLDARG_PTR and
>      NEWARG_PTR with the offending arguments if they are non-NULL.  */
>   
> -int
> +bool
>   comp_template_args (tree oldargs, tree newargs,
> -		    tree *oldarg_ptr, tree *newarg_ptr,
> -		    bool partial_order)
> +		    tree *oldarg_ptr /* = NULL */, tree *newarg_ptr /* = NULL */,
> +		    bool partial_order /* = false */)
>   {
> -  int i;
> -
>     if (oldargs == newargs)
> -    return 1;
> +    return true;
>   
>     if (!oldargs || !newargs)
> -    return 0;
> +    return false;
>   
>     if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
> -    return 0;
> +    return false;
>   
> -  for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
> +  for (int i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
>       {
>         tree nt = TREE_VEC_ELT (newargs, i);
>         tree ot = TREE_VEC_ELT (oldargs, i);
> @@ -9399,10 +9397,10 @@ comp_template_args (tree oldargs, tree newargs,
>   	    *oldarg_ptr = ot;
>   	  if (newarg_ptr != NULL)
>   	    *newarg_ptr = nt;
> -	  return 0;
> +	  return false;
>   	}
>       }
> -  return 1;
> +  return true;
>   }
>   
>   inline bool