Subject: [Boost-commit] svn:boost r57141 - sandbox/committee/rvalue_ref
From: dgregor_at_[hidden]
Date: 2009-10-24 14:49:21
Author: dgregor
Date: 2009-10-24 14:49:20 EDT (Sat, 24 Oct 2009)
New Revision: 57141
URL: http://svn.boost.org/trac/boost/changeset/57141
Log:
Update noexcept paper per CWG review
Text files modified:
sandbox/committee/rvalue_ref/N2983-throwing-move.rst | 100 ++++++++++++++++-----------------------
sandbox/committee/rvalue_ref/N2983.html | 87 ++++++++++++++--------------------
2 files changed, 78 insertions(+), 109 deletions(-)
Modified: sandbox/committee/rvalue_ref/N2983-throwing-move.rst
==============================================================================
--- sandbox/committee/rvalue_ref/N2983-throwing-move.rst (original)
+++ sandbox/committee/rvalue_ref/N2983-throwing-move.rst 2009-10-24 14:49:20 EDT (Sat, 24 Oct 2009)
@@ -272,6 +272,7 @@
reasonably easily migrated. However, we don't think this change would
be appropriate for C++0x at this late date, so we're not proposing it.
+FIXME: Add some discussion about implementation freedom with noexcept(true).
Proposed Changes to Standard Wording
************************************
@@ -290,7 +291,7 @@
.. role:: raw-html(raw)
:format: html
-
+
2.12 Keywords [lex.key]
=======================
@@ -301,7 +302,7 @@
Modify paragraph 3 as follows:
- 3 An allocation function that fails to allocate storage can invoke the currently installed new-handler function (18.6.2.3), if any. [ *Note*: A program-supplied allocation function can obtain the address of the currently installed new_handler using the ``std::set_new_handler`` function (18.6.2.4). -- *end note* ] If an allocation function declared with an empty *exception-specification* (15.4), :del:`throw(),` fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall indicate failure only by throwing an exception of a type that would match a handler (15.3) of type ``std::bad_alloc`` (18.6.2.1).
+ 3 An allocation function that fails to allocate storage can invoke the currently installed new-handler function (18.6.2.3), if any. [ *Note*: A program-supplied allocation function can obtain the address of the currently installed new_handler using the ``std::set_new_handler`` function (18.6.2.4). -- *end note* ] If an allocation function declared with :del:`an empty` :ins:`a non-throwing` *exception-specification* (15.4), :del:`throw(),` fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall indicate failure only by throwing an exception of a type that would match a handler (15.3) of type ``std::bad_alloc`` (18.6.2.1).
5.3 Unary expressions [expr.unary]
==================================
@@ -312,32 +313,32 @@
.. parsed-literal::
- unary-expression:
- postfix-expression
- ++ cast-expression
- -- cast-expression
- unary-operator cast-expression
- sizeof unary-expression
- sizeof ( type-id )
- sizeof ... ( identifier )
- alignof ( type-id )
- new-expression
- delete-expression
+ *unary-expression*:
+ *postfix-expression*
+ ++ *cast-expression*
+ -- *cast-expression*
+ *unary-operator* *cast-expression*
+ sizeof *unary-expression*
+ sizeof ( *type-id* )
+ sizeof ... ( *identifier* )
+ alignof ( *type-id* )
:raw-html:`<span class="ins"><i>noexcept-expression</i></span>`
+ *new-expression*
+ *delete-expression*
5.3.4 New [expr.new]
====================
Modify paragraph 13 as follows:
- 13 [Note: unless an allocation function is declared with an empty exception-specification (15.4), :del:`throw(),` it indicates failure to allocate storage by throwing a ``std::bad_alloc`` exception (Clause 15, 18.6.2.1); it returns a non-null pointer otherwise. If the allocation function is declared with an empty *exception-specification*, :del:`throw(),` it returns null to indicate failure to allocate storage and a non-null pointer otherwise. -- *end note*] If the allocation function returns null, initialization shall not be done, the deallocation function shall not be called, and the value of the new-expression shall be null.
+ 13 [*Note*: unless an allocation function is declared with :del:`an empty` :ins:`a non-throwing` *exception-specification* (15.4), :del:`throw(),` it indicates failure to allocate storage by throwing a ``std::bad_alloc`` exception (Clause 15, 18.6.2.1); it returns a non-null pointer otherwise. If the allocation function is declared with :del:`an empty` :ins:`a non-throwing` *exception-specification*, :del:`throw(),` it returns null to indicate failure to allocate storage and a non-null pointer otherwise. -- *end note*] If the allocation function returns null, initialization shall not be done, the deallocation function shall not be called, and the value of the new-expression shall be null.
5.3.7 noexcept operator [expr.unary.noexcept]
=============================================
(Add this new section)
- 1 :ins:`The noexcept operator determines whether the evaluation of its operand, which is an unevaluated operand (Clause 5), can throw an exception ([except.throw]).`
+ 1 :ins:`The noexcept operator determines whether the evaluation of its operand, which is an unevaluated operand ([expr] Clause 5), can throw an exception ([except.throw]).`
.. parsed-literal::
@@ -348,7 +349,7 @@
3 :raw-html:`<span class="ins">The result of the <code>noexcept</code> operator is <code>false</code> if in an evaluated context the <i>expression</i> would contain</span>`
- * :raw-html:`<span class="ins">a potentially evaluated call [<i>Footnote</i>: This includes implicit calls, e.g., the call to an allocation function in a <i>new-expression</i>. -- <i>end footnote</i>] to a function, member function, function pointer, or member function pointer that does not have an empty <i>exception-specification</i> ([except.spec]),</span>`
+ * :raw-html:`<span class="ins">a potentially evaluated call [<i>Footnote</i>: This includes implicit calls, e.g., the call to an allocation function in a <i>new-expression</i>. -- <i>end footnote</i>] to a function, member function, function pointer, or member function pointer that does not have a non-throwing <i>exception-specification</i> ([except.spec]),</span>`
* :raw-html:`<span class="ins">a potentially evaluated <i>throw-expression</i> ([except.throw]),</span>`
@@ -401,50 +402,33 @@
or indirectly throw by using an *exception-specification* as a suffix of its
declarator.
- :raw-html:`<p><em>
- exception-specification:
- <blockquote class="grammar">
- <span class="ins">dynamic-exception-specification</span>
- <br />
- <span class="ins">noexcept-specification</span>
- </blockquote>
- </em></p>`
-
- :raw-html:`<p><span class="ins">
- <em>dynamic-exception-specification:</em>
- </span>
- <blockquote>
- <code>throw (</code> <em>type-id-list<span class="sub">opt</span></em> <code>)</code>
- </blockquote>
- </p>`
-
- :raw-html:`<p><em>
- type-id-list:
- <blockquote>
- type-id ...<span class="sub">opt</span><br />
- type-id-list, type-id ...<span class="sub">opt</span>
- </blockquote>
- </em>
- </p>`
-
- :raw-html:`<p>
- <span class="ins"><em>noexcept-specification:</em></span>
- <blockquote>
- <span class="ins"><code>noexcept (</code> <em>constant-expression<span class="sub">opt</span></em> <code>)</code></span>
- </blockquote>
- </p>`
-
- :raw-html:`<span class="ins">In a <i>noexcept-specification</i>, the
- <i>constant-expression</i>, if supplied, shall be a constant expression
- ([expr.const]) that is contextually converted to <code>bool</code>
- ([conv] Clause 4). In what follows, a <i>noexcept-specification</i>
- <code>noexcept()</code> is equivalent to <code>noexcept(true)</code>.</span>`
+ .. parsed-literal::
+
+ *exception-specification:*
+ :raw-html:`<span class="ins"><i>dynamic-exception-specification</i></span>`
+ :raw-html:`<span class="ins"><i>noexcept-specification</i></span>`
+
+ :raw-html:`<span class="ins"><i>dynamic-exception-specification</i>:</span>`
+ :raw-html:`<span class="ins"><code>throw (</code> <em>type-id-list<sub>opt</sub></em> <code>)</code></span>`
+
+ *type-id-list*:
+ *type-id* :raw-html:`<code>...</code><sub><i>opt</i></sub>`
+ *type-id-list*, *type-id* :raw-html:`<code>...</code><sub><i>opt</i></sub>`
+
+ :raw-html:`<span class="ins"><em>noexcept-specification:</em></span>`
+ :raw-html:`<span class="ins"><code>noexcept (</code> <em>constant-expression<span class="sub">opt</span></em> <code>)</code></span>`
+
+ :raw-html:`<span class="ins">In a <i>noexcept-specification</i>, the
+ <i>constant-expression</i>, if supplied, shall be a constant expression
+ ([expr.const]) that is contextually converted to <code>bool</code>
+ ([conv] Clause 4). A <i>noexcept-specification</i>
+ <code>noexcept()</code> is equivalent to <code>noexcept(true)</code>.</span>`
7 A function is said to *allow* an exception of type ``E`` if its :raw-html:`<i><span class="ins">dynamic-</span>exception-specification</i>` contains a type ``T`` for which a handler of type ``T`` would be a match (15.3) for an exception of type ``E``.
.. comment :raw-html:`<span class="ins">, if its <i>noexcept-specification</i> is <code>noexcept(false)</code>, or if the function has no <i>exception-specification</i>`.
- 11 A function with no *exception-specification* :raw-html:`<span class="ins">, or with an <i>exception-specification</i> of the form <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> is <code>false</code>,</span>` allows all exceptions. :raw-html:`<span class="ins">An <i>exception-specification</i> is <i>empty</i> if it is of the form <code>throw()</code>, <code>noexcept()</code>, or <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> is <code>true</code>.</span>` A function with an empty *exception-specification* :raw-html:`<span class="del">, <code>throw()</code>,</span>` does not allow any exceptions.
+ 11 A function with no *exception-specification* :raw-html:`<span class="ins">, or with an <i>exception-specification</i> of the form <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> yields <code>false</code>,</span>` allows all exceptions. :raw-html:`<span class="ins">An <i>exception-specification</i> is <i>non-throwing</i> if it is of the form <code>throw()</code>, <code>noexcept()</code>, or <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> yields <code>true</code>.</span>` A function with :del:`an empty` :ins:`a non-throwing` *exception-specification* :raw-html:`<span class="del">, <code>throw()</code>,</span>` does not allow any exceptions.
14 In :raw-html:`a<span class="del">n</span> <i><span class="ins">dynamic-</span>exception-specification</i>,` a *type-id* followed by an ellipsis is a pack expansion (14.6.3).
@@ -453,10 +437,10 @@
:raw-html:`<span class="ins">15 If a function with a
<i>noexcept-specification</i> whose <i>constant-expression</i>
yields <code>true</code> throws an exception, the behavior is
- undefined. The <i>exception-specification</i> whose
+ undefined. A <i>noexcept-specification</i> whose
<i>constant-expression</i> yields <code>true</code> is in all
other respects equivalent to the <i>exception-specification</i>
- <code>throw()</code>. The <i>exception-specification</i> whose
+ <code>throw()</code>. A <i>noexcept-specification</i> whose
<i>constant-expression</i> yields <code>false</code> is equivalent
to omitting the <i>exception-specification</i> altogether.</span>`
@@ -467,7 +451,7 @@
Modify footnote 192 (the first footnote in paragraph 2) as follows:
- 192) That is, the C library functions can all be treated as if they have :del:`a throw()` :ins:`an empty` exception-specification. This allows implementations to make performance optimizations based on the absence of exceptions at runtime.
+ 192) That is, the C library functions can all be treated as if they have :del:`a throw()` :ins:`:del:`an empty` :ins:`a non-throwing`` exception-specification. This allows implementations to make performance optimizations based on the absence of exceptions at runtime.
18.8.2.2 Type unexpected_handler [unexpected.handler]
=====================================================
Modified: sandbox/committee/rvalue_ref/N2983.html
==============================================================================
--- sandbox/committee/rvalue_ref/N2983.html (original)
+++ sandbox/committee/rvalue_ref/N2983.html 2009-10-24 14:49:20 EDT (Sat, 24 Oct 2009)
@@ -586,6 +586,7 @@
where used properly, ought to be a well-known “caution area†that is
reasonably easily migrated. However, we don't think this change would
be appropriate for C++0x at this late date, so we're not proposing it.</p>
+<p>FIXME: Add some discussion about implementation freedom with noexcept(true).</p>
</div>
<div class="section" id="proposed-changes-to-standard-wording">
<h1><a class="toc-backref" href="#id15">Proposed Changes to Standard Wording</a></h1>
@@ -597,7 +598,7 @@
<h2><a class="toc-backref" href="#id17">3.7.4.1 Allocation functions [basic.stc.dynamic.allocation]</a></h2>
<p>Modify paragraph 3 as follows:</p>
<blockquote>
-3 An allocation function that fails to allocate storage can invoke the currently installed new-handler function (18.6.2.3), if any. [ <em>Note</em>: A program-supplied allocation function can obtain the address of the currently installed new_handler using the <tt class="docutils literal"><span class="pre">std::set_new_handler</span></tt> function (18.6.2.4). -- <em>end note</em> ] If an allocation function declared with an empty <em>exception-specification</em> (15.4), <span class="del">throw(),</span> fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall indicate failure only by throwing an exception of a type that would match a handler (15.3) of type <tt class="docutils literal"><span class="pre">std::bad_alloc</span></tt> (18.6.2.1).</blockquote>
+3 An allocation function that fails to allocate storage can invoke the currently installed new-handler function (18.6.2.3), if any. [ <em>Note</em>: A program-supplied allocation function can obtain the address of the currently installed new_handler using the <tt class="docutils literal"><span class="pre">std::set_new_handler</span></tt> function (18.6.2.4). -- <em>end note</em> ] If an allocation function declared with <span class="del">an empty</span> <span class="ins">a non-throwing</span> <em>exception-specification</em> (15.4), <span class="del">throw(),</span> fails to allocate storage, it shall return a null pointer. Any other allocation function that fails to allocate storage shall indicate failure only by throwing an exception of a type that would match a handler (15.3) of type <tt class="docutils literal"><span class="pre">std::bad_alloc</span></tt> (18.6.2.1).</blockquote>
</div>
<div class="section" id="unary-expressions-expr-unary">
<h2><a class="toc-backref" href="#id18">5.3 Unary expressions [expr.unary]</a></h2>
@@ -605,18 +606,18 @@
<blockquote>
<p>1 Expressions with unary operators group right-to-left.</p>
<pre class="literal-block">
-unary-expression:
- postfix-expression
- ++ cast-expression
- -- cast-expression
- unary-operator cast-expression
- sizeof unary-expression
- sizeof ( type-id )
- sizeof ... ( identifier )
- alignof ( type-id )
- new-expression
- delete-expression
+<em>unary-expression</em>:
+ <em>postfix-expression</em>
+ ++ <em>cast-expression</em>
+ -- <em>cast-expression</em>
+ <em>unary-operator</em> <em>cast-expression</em>
+ sizeof <em>unary-expression</em>
+ sizeof ( <em>type-id</em> )
+ sizeof ... ( <em>identifier</em> )
+ alignof ( <em>type-id</em> )
<span class="raw-html"><span class="ins"><i>noexcept-expression</i></span></span>
+ <em>new-expression</em>
+ <em>delete-expression</em>
</pre>
</blockquote>
</div>
@@ -624,13 +625,13 @@
<h2><a class="toc-backref" href="#id19">5.3.4 New [expr.new]</a></h2>
<p>Modify paragraph 13 as follows:</p>
<blockquote>
-13 [Note: unless an allocation function is declared with an empty exception-specification (15.4), <span class="del">throw(),</span> it indicates failure to allocate storage by throwing a <tt class="docutils literal"><span class="pre">std::bad_alloc</span></tt> exception (Clause 15, 18.6.2.1); it returns a non-null pointer otherwise. If the allocation function is declared with an empty <em>exception-specification</em>, <span class="del">throw(),</span> it returns null to indicate failure to allocate storage and a non-null pointer otherwise. -- <em>end note</em>] If the allocation function returns null, initialization shall not be done, the deallocation function shall not be called, and the value of the new-expression shall be null.</blockquote>
+13 [<em>Note</em>: unless an allocation function is declared with <span class="del">an empty</span> <span class="ins">a non-throwing</span> <em>exception-specification</em> (15.4), <span class="del">throw(),</span> it indicates failure to allocate storage by throwing a <tt class="docutils literal"><span class="pre">std::bad_alloc</span></tt> exception (Clause 15, 18.6.2.1); it returns a non-null pointer otherwise. If the allocation function is declared with <span class="del">an empty</span> <span class="ins">a non-throwing</span> <em>exception-specification</em>, <span class="del">throw(),</span> it returns null to indicate failure to allocate storage and a non-null pointer otherwise. -- <em>end note</em>] If the allocation function returns null, initialization shall not be done, the deallocation function shall not be called, and the value of the new-expression shall be null.</blockquote>
</div>
<div class="section" id="noexcept-operator-expr-unary-noexcept">
<h2><a class="toc-backref" href="#id20">5.3.7 noexcept operator [expr.unary.noexcept]</a></h2>
<p>(Add this new section)</p>
<blockquote>
-<p>1 <span class="ins">The noexcept operator determines whether the evaluation of its operand, which is an unevaluated operand (Clause 5), can throw an exception ([except.throw]).</span></p>
+<p>1 <span class="ins">The noexcept operator determines whether the evaluation of its operand, which is an unevaluated operand ([expr] Clause 5), can throw an exception ([except.throw]).</span></p>
<pre class="literal-block">
<span class="raw-html"><span class="ins"><i>noexcept-expression</i></span></span>
<span class="raw-html"><span class="ins">noexcept ( <i>expression</i> )</span></span>
@@ -638,7 +639,7 @@
<p>2 <span class="raw-html"><span class="ins">The result of the <code>noexcept</code> operator is a constant of type <code>bool</code>.</span></span></p>
<p>3 <span class="raw-html"><span class="ins">The result of the <code>noexcept</code> operator is <code>false</code> if in an evaluated context the <i>expression</i> would contain</span></span></p>
<ul class="simple">
-<li><span class="raw-html"><span class="ins">a potentially evaluated call [<i>Footnote</i>: This includes implicit calls, e.g., the call to an allocation function in a <i>new-expression</i>. -- <i>end footnote</i>] to a function, member function, function pointer, or member function pointer that does not have an empty <i>exception-specification</i> ([except.spec]),</span></span></li>
+<li><span class="raw-html"><span class="ins">a potentially evaluated call [<i>Footnote</i>: This includes implicit calls, e.g., the call to an allocation function in a <i>new-expression</i>. -- <i>end footnote</i>] to a function, member function, function pointer, or member function pointer that does not have a non-throwing <i>exception-specification</i> ([except.spec]),</span></span></li>
<li><span class="raw-html"><span class="ins">a potentially evaluated <i>throw-expression</i> ([except.throw]),</span></span></li>
<li><span class="raw-html"><span class="ins">a potentially evaluated <code>dynamic_cast</code> expression <code>dynamic_cast<T>(v)</code>, where <code>T</code> is a reference type, that requires a run-time check ([expr.dynamic.cast]), or</span></span></li>
<li><span class="raw-html"><span class="ins">a potentially evaluated <code>typeid</code> expression ([expr.typeid]) applied to an expression whose type is a polymorphic class type ([class.virtual]).</span></span></li>
@@ -688,45 +689,29 @@
<p>1 A function declaration lists exceptions that its function might directly
or indirectly throw by using an <em>exception-specification</em> as a suffix of its
declarator.</p>
-<blockquote>
-<p><span class="raw-html"><p><em>
-exception-specification:
-<blockquote class="grammar">
-<span class="ins">dynamic-exception-specification</span>
-<br />
-<span class="ins">noexcept-specification</span>
-</blockquote>
-</em></p></span></p>
-<p><span class="raw-html"><p><span class="ins">
-<em>dynamic-exception-specification:</em>
-</span>
-<blockquote>
-<code>throw (</code> <em>type-id-list<span class="sub">opt</span></em> <code>)</code>
-</blockquote>
-</p></span></p>
-<p><span class="raw-html"><p><em>
-type-id-list:
-<blockquote>
-type-id ...<span class="sub">opt</span><br />
-type-id-list, type-id ...<span class="sub">opt</span>
-</blockquote>
-</em>
-</p></span></p>
-<p><span class="raw-html"><p>
-<span class="ins"><em>noexcept-specification:</em></span>
-<blockquote>
-<span class="ins"><code>noexcept (</code> <em>constant-expression<span class="sub">opt</span></em> <code>)</code></span>
-</blockquote>
-</p></span></p>
+<pre class="literal-block">
+<em>exception-specification:</em>
+ <span class="raw-html"><span class="ins"><i>dynamic-exception-specification</i></span></span>
+ <span class="raw-html"><span class="ins"><i>noexcept-specification</i></span></span>
+
+<span class="raw-html"><span class="ins"><i>dynamic-exception-specification</i>:</span></span>
+ <span class="raw-html"><span class="ins"><code>throw (</code> <em>type-id-list<sub>opt</sub></em> <code>)</code></span></span>
+
+<em>type-id-list</em>:
+ <em>type-id</em> <span class="raw-html"><code>...</code><sub><i>opt</i></sub></span>
+ <em>type-id-list</em>, <em>type-id</em> <span class="raw-html"><code>...</code><sub><i>opt</i></sub></span>
+
+<span class="raw-html"><span class="ins"><em>noexcept-specification:</em></span></span>
+ <span class="raw-html"><span class="ins"><code>noexcept (</code> <em>constant-expression<span class="sub">opt</span></em> <code>)</code></span></span>
+</pre>
<p><span class="raw-html"><span class="ins">In a <i>noexcept-specification</i>, the
<i>constant-expression</i>, if supplied, shall be a constant expression
([expr.const]) that is contextually converted to <code>bool</code>
-([conv] Clause 4). In what follows, a <i>noexcept-specification</i>
+([conv] Clause 4). A <i>noexcept-specification</i>
<code>noexcept()</code> is equivalent to <code>noexcept(true)</code>.</span></span></p>
-</blockquote>
<p>7 A function is said to <em>allow</em> an exception of type <tt class="docutils literal"><span class="pre">E</span></tt> if its <span class="raw-html"><i><span class="ins">dynamic-</span>exception-specification</i></span> contains a type <tt class="docutils literal"><span class="pre">T</span></tt> for which a handler of type <tt class="docutils literal"><span class="pre">T</span></tt> would be a match (15.3) for an exception of type <tt class="docutils literal"><span class="pre">E</span></tt>.</p>
<!-- comment :raw-html:`<span class="ins">, if its <i>noexcept-specification</i> is <code>noexcept(false)</code>, or if the function has no <i>exception-specification</i>`. -->
-<p>11 A function with no <em>exception-specification</em> <span class="raw-html"><span class="ins">, or with an <i>exception-specification</i> of the form <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> is <code>false</code>,</span></span> allows all exceptions. <span class="raw-html"><span class="ins">An <i>exception-specification</i> is <i>empty</i> if it is of the form <code>throw()</code>, <code>noexcept()</code>, or <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> is <code>true</code>.</span></span> A function with an empty <em>exception-specification</em> <span class="raw-html"><span class="del">, <code>throw()</code>,</span></span> does not allow any exceptions.</p>
+<p>11 A function with no <em>exception-specification</em> <span class="raw-html"><span class="ins">, or with an <i>exception-specification</i> of the form <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> yields <code>false</code>,</span></span> allows all exceptions. <span class="raw-html"><span class="ins">An <i>exception-specification</i> is <i>non-throwing</i> if it is of the form <code>throw()</code>, <code>noexcept()</code>, or <code>noexcept(<i>constant-expression</i>)</code> where the <i>constant-expression</i> yields <code>true</code>.</span></span> A function with <span class="del">an empty</span> <span class="ins">a non-throwing</span> <em>exception-specification</em> <span class="raw-html"><span class="del">, <code>throw()</code>,</span></span> does not allow any exceptions.</p>
<p>14 In <span class="raw-html">a<span class="del">n</span> <i><span class="ins">dynamic-</span>exception-specification</i>,</span> a <em>type-id</em> followed by an ellipsis is a pack expansion (14.6.3).</p>
</blockquote>
<p>Add the following new paragraph:</p>
@@ -734,10 +719,10 @@
<span class="raw-html"><span class="ins">15 If a function with a
<i>noexcept-specification</i> whose <i>constant-expression</i>
yields <code>true</code> throws an exception, the behavior is
-undefined. The <i>exception-specification</i> whose
+undefined. A <i>noexcept-specification</i> whose
<i>constant-expression</i> yields <code>true</code> is in all
other respects equivalent to the <i>exception-specification</i>
-<code>throw()</code>. The <i>exception-specification</i> whose
+<code>throw()</code>. A <i>noexcept-specification</i> whose
<i>constant-expression</i> yields <code>false</code> is equivalent
to omitting the <i>exception-specification</i> altogether.</span></span></blockquote>
<!-- comment
@@ -747,7 +732,7 @@
Modify footnote 192 (the first footnote in paragraph 2) as follows:
- 192) That is, the C library functions can all be treated as if they have :del:`a throw()` :ins:`an empty` exception-specification. This allows implementations to make performance optimizations based on the absence of exceptions at runtime. -->
+ 192) That is, the C library functions can all be treated as if they have :del:`a throw()` :ins:`:del:`an empty` :ins:`a non-throwing`` exception-specification. This allows implementations to make performance optimizations based on the absence of exceptions at runtime. -->
</div>
<div class="section" id="type-unexpected-handler-unexpected-handler">
<h2><a class="toc-backref" href="#id25">18.8.2.2 Type unexpected_handler [unexpected.handler]</a></h2>