Re: [PATCH v1.1 1/3] Introduce gdb::function_view

[Yao Qi <qiyaoltc@gmail.com>]

On 17-02-22 17:49:22, Pedro Alves wrote:
> On 02/22/2017 05:40 PM, Pedro Alves wrote:
> 
> > I'll send the updated (squashed) patch as a reply.
> 
> Here is is.  Thanks for the quick review!
> 
> From 997f0e94cbd2d1cdb4bf7612df1de72ce1a6eb56 Mon Sep 17 00:00:00 2001
> From: Pedro Alves <palves@redhat.com>
> Date: Wed, 22 Feb 2017 17:43:09 +0000
> Subject: [PATCH] Introduce gdb::function_view
> 
> This commit adds new function_view type.  This type holds a a

Double "a" at the end.

> non-owning reference to a callable.  It is meant to be used as
> callback type of functions, instead of using C-style pair of function
> pointer and 'void *data' arguments.  function_view allows passing
> references to stateful function objects / lambdas w/ captures as
> callbacks efficiently, while function pointer + 'void *' does not.
> 
> See the intro in the new function-view.h header for more.
> 
> Unit tests included.  I added a new gdb/unittests/ subdir this time,
> instead of putting the tests under gdb/.  If this is agreed to be a
> good idea, some of the current selftests that exercise gdb/common/
> things but live in gdb/ could move here (e.g., gdb/utils-selftests.c).

I wanted to add gdb/unittests for a while, but didn't have a chance to
do so.  Yes, it is a good idea to me.  How is GDB unit tests, like
disasm-selftests.c?  Do you want to move it to gdb/unittests/?

> +   C++11 gave us std::function as type-erased wrapper around arbitrary
> +   callables, however, std::function is not an ideal fit for transient
> +   callbacks such as the use case above.  For this use case, which is
> +   quite pervasive, a function_view is a better choice, because while
> +   while function_view is light and does not require any heap

Double "while"s.

> +namespace gdb {
> +

This is a new namespace in gdb source.  What is the rule of using this
namespace?

-- 
Yao