Skip to content

Update PR for 4591 #626

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
jwakely merged 1 commit into from
Sep 11, 2026
Merged

Update PR for 4591 #626

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
70 changes: 55 additions & 15 deletions xml/issue4591.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,12 +10,12 @@

<discussion>
<p>
`std::meta::current_function` is specified to throw if <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>
does not represent a function. It is implied that `current_function` throws if the call is
`std::meta::current_function` is specified to throw if <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>
does not represent a function. It is implied that `current_function` throws if the call is
directly contained in a local class, in which case it's actually in a function body, but indirectly.
<p/>
This might be an oversight, as neither <paper num="P3795"/> (which introduced this function) nor
<a href="https://wg21.link/P3795/github">https://wg21.link/P3795/github</a> has any discussion
This might be an oversight, as neither <paper num="P3795"/> (which introduced this function) nor
<a href="https://wg21.link/P3795/github">https://wg21.link/P3795/github</a> has any discussion
concerning local classes.
<p/>
Example:
Expand Down Expand Up @@ -48,14 +48,14 @@ consteval info current_function();
</pre>
<blockquote>
<p>
-6- An invocation of `current_function` that appears at a program point <tt><i>P</i></tt>
is value-dependent (<sref ref="[temp.dep.constexpr]"/>) if <tt><i>eval-point</i>(<i>P</i>)</tt>
-6- An invocation of `current_function` that appears at a program point <tt><i>P</i></tt>
is value-dependent (<sref ref="[temp.dep.constexpr]"/>) if <tt><i>eval-point</i>(<i>P</i>)</tt>
is enclosed by a scope corresponding to a templated entity.
<p/>
-7- Let <tt><i>S</i></tt> be <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>, where <tt><i>P</i></tt>
-7- Let <tt><i>S</i></tt> be <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>, where <tt><i>P</i></tt>
is the point at which the invocation of `current_function` lexically appears.
<p/>
-8- <i>Returns</i>: <tt><i>S</i></tt> <ins>if <tt><i>S</i></tt> represents a function. Otherwise,
-8- <i>Returns</i>: <tt><i>S</i></tt> <ins>if <tt><i>S</i></tt> represents a function. Otherwise,
<tt>parent_of(<i>S</i>)</tt></ins>.
<p/>
-9- <i>Throws</i>: `meta::exception` unless <tt><i>S</i></tt> represents a function.
Expand All @@ -77,6 +77,46 @@ Set priority to 2 after reflector poll.
<p>
"we should say this in words, similar to `current_namespace`."
</p>
<superseded>
<p>
This wording is relative to <paper num="N5046"/>.
</p>

<ol>
<li>
<p>Modify <sref ref="[meta.reflection.scope]"/> as indicated:</p>

<blockquote>
<pre>
consteval info current_function();
</pre>
<blockquote>
<p>
-6- An invocation of `current_function` that appears at a program point <tt><i>P</i></tt>
is value-dependent (<sref ref="[temp.dep.constexpr]"/>) if <tt><i>eval-point</i>(<i>P</i>)</tt>
is enclosed by a scope corresponding to a templated entity.
<p/>
-7- Let <tt><i>S</i></tt> be <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>, where <tt><i>P</i></tt>
is the point at which the invocation of `current_function` lexically appears.
<p/>
-8- <i>Returns</i>: <tt><i>S</i></tt> <ins>if <tt><i>S</i></tt> represents a function.
Otherwise, a reflection representing the nearest enclosing
function of the entity represented by <tt><i>S</i></tt></ins>.
<p/>
-9- <i>Throws</i>: `meta::exception` unless <del><tt><i>S</i></tt> represents a
function</del><ins>an enclosing function is found</ins>.
</p>
</blockquote>
</blockquote>

</li>

</ol>
</superseded>

<note>2026-09-11; Tim provides new wording</note>
<p>The invented lambdas from consteval-block-declarations need to be ignored.</p>

</discussion>

<resolution>
Expand All @@ -94,19 +134,19 @@ consteval info current_function();
</pre>
<blockquote>
<p>
-6- An invocation of `current_function` that appears at a program point <tt><i>P</i></tt>
is value-dependent (<sref ref="[temp.dep.constexpr]"/>) if <tt><i>eval-point</i>(<i>P</i>)</tt>
-6- An invocation of `current_function` that appears at a program point <tt><i>P</i></tt>
is value-dependent (<sref ref="[temp.dep.constexpr]"/>) if <tt><i>eval-point</i>(<i>P</i>)</tt>
is enclosed by a scope corresponding to a templated entity.
<p/>
-7- Let <tt><i>S</i></tt> be <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>, where <tt><i>P</i></tt>
-7- Let <tt><i>S</i></tt> be <tt><i>CURRENT-SCOPE</i>(<i>P</i>)</tt>, where <tt><i>P</i></tt>
is the point at which the invocation of `current_function` lexically appears.
<p/>
-8- <i>Returns</i>: <tt><i>S</i></tt> <ins>if <tt><i>S</i></tt> represents a function.
-8- <i>Returns</i>: <tt><i>S</i></tt> <ins>if <tt><i>S</i></tt> represents a function.
Otherwise, a reflection representing the nearest enclosing
function of the entity represented by <tt><i>S</i></tt></ins>.
function of the entity represented by <tt><i>S</i></tt>, ignoring any function call operators of closure types introduced by <i>consteval-block-declaration</i>s (<sref ref="[dcl.pre]"/>)</ins>.
<p/>
-9- <i>Throws</i>: `meta::exception` unless <del><tt><i>S</i></tt> represents a
function</del><ins>an enclosing function is found</ins>.
-9- <i>Throws</i>: `meta::exception` <del>unless</del><ins>if</ins> <tt><i>S</i></tt> <ins>does not represent</ins><del>represents</del> a
function <ins>and an enclosing function is not found</ins>.
</p>
</blockquote>
</blockquote>
Expand Down