|
|
Boost-Commit : |
Subject: [Boost-commit] svn:boost r48665 - sandbox/committee/concepts/wording
From: dgregor_at_[hidden]
Date: 2008-09-08 10:02:16
Author: dgregor
Date: 2008-09-08 10:02:15 EDT (Mon, 08 Sep 2008)
New Revision: 48665
URL: http://svn.boost.org/trac/boost/changeset/48665
Log:
Prep the next revision of the concepts wording
Text files modified:
sandbox/committee/concepts/wording/wording.tex | 250 +++++++++++----------------------------
1 files changed, 72 insertions(+), 178 deletions(-)
Modified: sandbox/committee/concepts/wording/wording.tex
==============================================================================
--- sandbox/committee/concepts/wording/wording.tex (original)
+++ sandbox/committee/concepts/wording/wording.tex 2008-09-08 10:02:15 EDT (Mon, 08 Sep 2008)
@@ -49,7 +49,7 @@
\huge
\begin{center}
Proposed Wording for Concepts\\
-(Revision 8)
+(Revision 9)
\end{center}
\normalsize
@@ -62,8 +62,8 @@
Jeremy Siek, University of Colorado at Boulder
\end{tabular}\vspace{-6pt}
-\par\noindent Document number: N2741=08-0251 \vspace{-6pt}
-\par\noindent Revises document number: N2710=08-0220 \vspace{-6pt}
+\par\noindent Document number: DRAFT \vspace{-6pt}
+\par\noindent Revises document number: N2741=08-0251 \vspace{-6pt}
\par\noindent Date: \today\vspace{-6pt}
\par\noindent Project: Programming Language \Cpp{}, Core Working Group\vspace{-6pt}
\par\noindent Reply-to: Douglas Gregor $<$\href{mailto:doug.gregor_at_[hidden]}{doug.gregor_at_[hidden]}$>$
@@ -105,75 +105,9 @@
\item N2654=08-0161: Allocator Concepts (Revision 1)
\end{itemize}
-\section*{Changes from N2710}
+\section*{Changes from N2741}
\begin{itemize}
-\item Removed the deprecation of \tcode{late_check}.
-
-\item Clarified how a ``call to an associated function candidate set''
- actually works in the \techterm{pseudo-destructor-name} and
- ``initialization of an object'' cases
- (\ref{temp.constrained.inst}). For example:
-\begin{codeblock}
-auto concept DefaultConstructible<typename T> {
- T::T();
-}
-
-template<DefaultConstructible T>
-void f() {
- T t1; // type-checks as a call to \tcode{DefaultConstructible<T>}'s \tcode{T::T()}
- T t2{}; // type-checks as a call to \tcode{DefaultConstructible<T>}'s \tcode{T::T()}
-}
-
-template void f<int>(); // \tcode{t1} is not initialized, \tcode{t2} is value-initialized
-\end{codeblock}
-
-\item The \tcode{MoveConstructible<T>} requirement is no longer
- propagated from the types of function parameters
- (\ref{temp.req.impl}). This change brings concepts in sync with
- generalized initializer lists (N2672), which permit a function
- parameter to be initialized without copying or moving.
-
-\item Made an expression that uses a constrained member in the current
- instantiation a type-dependent expression
- (\ref{temp.dep.expr}). This change is required to properly delay
- type-checking of, e.g., unconstrained templates that have
- constrained members:
-\begin{codeblock}
-template<typename T> struct list {
- requires C<T> void f(int);
- void g() { f(17); } // ``f'' is type-dependent, because it might or
- // might not exist in the instantiation.
-};
-\end{codeblock}
-
-\item Made default function arguments an unconstrained context
- (again), due to the realization that this change could cause a large
- increase in the number of constructors need for, e.g.,
- \tcode{unordered_map}. Please see c++std-core-13280 and
- c++std-ext-10456 for additional information.
-
-\item Clarified the point of declaration of a template requirement
- (\ref{basic.scope.pdecl}) and its potential scope
- (\ref{basic.scope.req}).
-
-\item Clarified that the requirements of a constrained member include
- the requirements of enclosing constrained templates
- (\ref{temp.class}).
-
-\item Rewrote the section describing the implicit definition of
- concept maps and concept map templates for refinements
- (\ref{concept.refine.maps}). The semantics have not changed, but the
- resulting wording should be much clearer.
-
-\item Specify precisely which built-in candidates get defined when
- archetypes are present (\ref{over.built}).
-
-\item Clarified the template requirements of the default
- implementations of associated functions (\ref{concept.fct}).
-
-\item Clarified the formation of retain candidate sets
- (\ref{temp.constrained.inst}) and of candidate sets themselves
- (\ref{temp.constrained.set}).
+\item Nothing yet.
\end{itemize}
\section*{Typographical conventions}
@@ -361,7 +295,7 @@
\mbox{\techterm{concept-map-definition}}.}
\pnum
-\addedCC{The point of declaration for a template requirement
+\addedConcepts{The point of declaration for a template requirement
(\mbox{\ref{temp.req}}) is immediately after the corresponding
\mbox{\techterm{requirement}} in a
\mbox{\techterm{requires-clause}} or the
@@ -408,13 +342,9 @@
concept map.}
\end{enumeraten}
-\pnum
-\removedCCC{The name of a concept member shall only be used in the
- scope of its concept (as described above).}
-
\rSec2[basic.scope.req]{Requirements scope}
\pnum
-\addedCC{A template requirement has \mbox{\techterm{requirements
+\addedConcepts{A template requirement has \mbox{\techterm{requirements
scope}}. Its potential scope begins at its point of declaration
and terminates at the end of the constrained template.}
@@ -666,11 +596,8 @@
\additemConcepts{
If the template argument list of the concept instance references a
template parameter or associated type of a requirement, and if the name,
-when looked up within the scope of the concept}
-\changedCCC{of}{(not}
-\addedConcepts{the concept instance}\addedCC{)}\addedConcepts{,}
-\removedCCC{unambiguously}
-\addedConcepts{refers to an associated type or class template, the result
+when looked up within the scope of the concept (not the concept instance),
+refers to an associated type or class template, the result
of name lookup is the associated type or class template as a member of the
requirement.
\mbox{\enternote}\ this implies that, given two distinct type parameters
@@ -976,12 +903,6 @@
}
\end{codeblock}
\exitexample\
-% \addedCC{
-% \mbox{\enternote}
-% this demonstrates the kind of template whose instantiations may
-% suffer from the dreaded ``dropped concept maps'' pitfall.
-% \mbox{\exitnote}
-% }
\pnum
@@ -1003,11 +924,6 @@
}
\pnum
-\removedCCC{
-The use of \mbox{\tcode{late\_check}} is deprecated.
-}
-
-\pnum
\addedConcepts{
\mbox{\enterrationale}
a late-checked block should be used only when certain suitably
@@ -1472,8 +1388,8 @@
A constrained member is
treated as a constrained template (\mbox{\ref{temp.constrained}})
whose template requirements include the requirements
- specified in its \mbox{\techterm{member-requirement}} clause}
-\addedCC{and the requirements of each enclosing constrained template}\addedConcepts{.}
+ specified in its \mbox{\techterm{member-requirement}} clause
+and the requirements of each enclosing constrained template.}
\end{paras}
\setcounter{chapter}{11}
@@ -2349,7 +2265,7 @@
\pnum
For every cv-qualified or cv-unqualified object type
-\textit{T}, \addedCC{including archetypes,}
+\textit{T}, \addedConcepts{including archetypes,}
there exist candidate operator functions of the form
\begin{codeblock}
@@ -2358,7 +2274,7 @@
\pnum
For every function type
-\textit{T}, \addedCC{including archetypes,}
+\textit{T}, \addedConcepts{including archetypes,}
there exist candidate operator functions of the form
\begin{codeblock}
@@ -2367,7 +2283,7 @@
\pnum
For every type
-\textit{T}, \addedCC{including archetypes for which the template requirements contain \mbox{\tcode{std::PointeeType<T>}},}
+\textit{T}, \addedConcepts{including archetypes for which the template requirements contain \mbox{\tcode{std::PointeeType<T>}},}
there exist candidate operator functions of the form
\begin{codeblock}
@@ -2377,7 +2293,7 @@
\setcounter{Paras}{12}
\pnum
For every cv-qualified or cv-unqualified object type
-\textit{T}, \addedCC{including archetypes,}
+\textit{T}, \addedConcepts{including archetypes,}
there exist candidate operator functions of the form
\begin{codeblock}
@@ -2393,16 +2309,16 @@
\textit{T},\
where
\textit{T}\
-is a pointer to object type, \addedCC{including pointers to archetypes,}
+is a pointer to object type, \addedConcepts{including pointers to archetypes,}
there exist candidate operator functions of the form
\begin{codeblock}
-std::ptrdiff_t operator-(@\textit{T}\addedCC{*}@, @\textit{T}\addedCC{*}@);
+std::ptrdiff_t operator-(@\textit{T}\addedConcepts{*}@, @\textit{T}\addedConcepts{*}@);
\end{codeblock}
\pnum
For every pointer or enumeration type
-\textit{T}, \addedCC{including pointers to archetypes,}
+\textit{T}, \addedConcepts{including pointers to archetypes,}
there exist candidate operator functions of the form
\begin{codeblock}
@@ -2416,7 +2332,7 @@
\pnum
For every pointer to member type
-\textit{T}, \addedCC{including pointer to member types involving archetypes,}
+\textit{T}, \addedConcepts{including pointer to member types involving archetypes,}
there exist candidate operator functions of the form
\begin{codeblock}
@@ -2431,8 +2347,8 @@
\textit{VQ}),
where
\textit{T}\
-is any type\addedCC{, including archetypes for which the template
- requirements contain}\\ \addedCC{\mbox{\tcode{std::PointeeType<T>}},}
+is any type\addedConcepts{, including archetypes for which the template
+ requirements contain}\\ \addedConcepts{\mbox{\tcode{std::PointeeType<T>}},}
and
\textit{VQ}\
is either
@@ -2450,7 +2366,7 @@
\textit{VQ}),
where
\textit{T}\
-is an enumeration or pointer to member type\addedCC{, including
+is an enumeration or pointer to member type\addedConcepts{, including
pointer to member types that involve archetypes,} and
\textit{VQ}\
is either
@@ -2468,7 +2384,7 @@
\textit{VQ}),
where
\textit{T}\
-is a cv-qualified or cv-unqualified object type\addedCC{, including archetypes,} and
+is a cv-qualified or cv-unqualified object type\addedConcepts{, including archetypes,} and
\textit{VQ}\
is either
\tcode{volatile}
@@ -2486,7 +2402,7 @@
\textit{T},
where
\textit{T}\
-is a pointer or pointer-to-member type, \addedCC{including pointer and
+is a pointer or pointer-to-member type, \addedConcepts{including pointer and
pointer-to-member types that involve archetypes,} there exist candidate operator
functions of the form
@@ -2724,9 +2640,8 @@
declared only in class template specializations in which its
template requirements (\mbox{\ref{temp.req}}) are satisfied. If there exist multiple
overloads of the constrained member with identical signatures, ignoring
- the template requirements,}
-\addedCC{and identical return types,}
-\addedConcepts{only the most specialized
+ the template requirements, and identical return types,
+only the most specialized
overload, as determined by partial ordering of the template requirements
(\mbox{\ref{temp.func.order}}), will be declared in the instantiation. If
partial ordering results in an ambiguity, a deleted function with
@@ -3366,7 +3281,7 @@
\techterm{qualified-id}\
that names a member of an unknown specialization.
-\additemCC{an \mbox{\techterm{identifier}}, \mbox{\techterm{nested-name-specifier}}, or a \mbox{\techterm{qualified-id}} that names a
+\additemConcepts{an \mbox{\techterm{identifier}}, \mbox{\techterm{nested-name-specifier}}, or a \mbox{\techterm{qualified-id}} that names a
member of the current instantiation that is a constrained member
(\mbox{\ref{class.mem}}).}
\end{itemize}
@@ -3955,7 +3870,7 @@
\addedConcepts{Associated functions may have a default implementation. This
implementation will be instantiated when used. A default implementation of an
associated function is a constrained template
-(\mbox{\ref{temp.constrained}})} \addedCC{whose template requirements
+(\mbox{\ref{temp.constrained}})} \addedConcepts{whose template requirements
include concept requirements for the enclosing concept, its
refinements, along with its
associated requirements}\addedConcepts{. \mbox{\enterexample}}
@@ -4960,8 +4875,7 @@
\additemConcepts{if \mbox{\tcode{f}} refers to an associated type in all concept
scopes in \mbox{\tcode{C$_{R'}$}}, and all of the associated types are
equivalent (\mbox{\ref{temp.req}}), the result is the associated
- type \mbox{\tcode{f}},} \removedCCC{found first by a depth-first traversal of the
- refinement clauses,}
+ type \mbox{\tcode{f}},}
\additemConcepts{otherwise, name lookup of \mbox{\tcode{f}} in \mbox{\tcode{C}} is ambiguous.}
\end{itemize}
@@ -5010,19 +4924,18 @@
\rSec3[concept.refine.maps]{Implicit concept maps for refined concepts}
\pnum
-\addedConcepts{When a concept map} \addedCC{or concept map template}
-\addedConcepts{is defined for a concept
- \mbox{\tcode{C}} that has a refinement clause, concept maps}
-\addedCC{or concept map templates}
-\addedConcepts{for each
+\addedConcepts{When a concept map or concept map template
+is defined for a concept
+ \mbox{\tcode{C}} that has a refinement clause, concept maps
+or concept map templates for each
of the concept instances in the
refinement clause of
\mbox{\tcode{C}}
-shall be defined,} \addedCC{implicitly or explicitly,}
-\addedConcepts{in the namespace of which the
-refining concept map} \addedCC{or concept map template}
-\addedConcepts{is a member.}
-\addedConcepts{\mbox{\enterexample}}
+shall be defined, implicitly or explicitly,
+in the namespace of which the
+refining concept map or concept map template
+is a member.
+\mbox{\enterexample}}
\begin{codeblock}
concept A<typename T> { }
concept B<typename T> : A<T> { }
@@ -5032,7 +4945,7 @@
\addedConcepts{\mbox{\exitexample}}
\pnum
-\addedCC{A concept map or concept map template for a refinement
+\addedConcepts{A concept map or concept map template for a refinement
(called a \mbox{\techterm{refined}} concept map or concept map
template) has been
defined if concept map lookup (\mbox{\ref{temp.req.sat}}) finds a
@@ -5046,9 +4959,8 @@
or if it finds a concept map from a different namespace, a suitable
concept map shall be defined implicitly, as described below.}
-
\pnum
-\addedCC{Concept map templates (\mbox{\ref{temp.concept.map}})
+\addedConcepts{Concept map templates (\mbox{\ref{temp.concept.map}})
can only be defined for certain refinements. A refined concept map
template corresponding to a particular
\mbox{\techterm{refinement-specifier}} can be
@@ -5090,7 +5002,7 @@
\addedConcepts{\mbox{\exitexample}}
\pnum
-\addedCC{When a refined concept map or concept map template is
+\addedConcepts{When a refined concept map or concept map template is
implicitly defined, definitions in the refining concept map or
concept map template can be
used to satisfy the requirements of the refined concept (\mbox{\ref{concept.map}}).
@@ -5218,7 +5130,7 @@
\additemConcepts{a late-checked block (\mbox{\ref{stmt.late}}),}
\additemConcepts{a default argument in a
\mbox{\techterm{template-parameter}}, and}
- \additemCC{a default function argument (\mbox{\ref{dcl.fct}}).}
+ \additemConcepts{a default function argument (\mbox{\ref{dcl.fct}}).}
\end{itemize}
\pnum
@@ -5542,7 +5454,7 @@
within a constrained context (\mbox{\ref{temp.constrained}}),
concept map archetypes, whose names are placed at the same scope as
template parameters, can be found by unqualified lookup.}
-\addedCC{Concept map lookup does not require the definition of a concept
+\addedConcepts{Concept map lookup does not require the definition of a concept
map archetype that it finds.}
\addedConcepts{\mbox{\exitnote}}
@@ -5657,12 +5569,10 @@
implied.}
\pnum
-\addedConcepts{The formation of types within}
-\addedCC{certain parts of}
-\addedConcepts{the declaration of a
- constrained template}
-\addedCC{(described above)}
-\addedConcepts{implies the template requirements needed to
+\addedConcepts{The formation of types within certain parts of
+the declaration of a
+ constrained template (described above)
+implies the template requirements needed to
ensure that the types themselves are well-formed within any
instantiation. The following type constructions imply template
requirements:}
@@ -5715,10 +5625,6 @@
return t + u;
}
\end{codeblock}
-
-\item \removedCCC{For every type archetype \mbox{\tcode{T}} that is the type
- of a parameter in a function type, the requirement
- \mbox{\tcode{MoveConstructible<T>}} is implied.}
\addedConcepts{\exitexample}
\end{itemize}
@@ -5760,9 +5666,9 @@
type, template, or value whose behavior is defined
by the template requirements (\mbox{\ref{temp.req}}) of its constrained
template. Within a constrained context
- (\mbox{\ref{temp.constrained}}), a}
-\changedCCC{template parameter}{type, value, or template that has an established archetype (described below)}
-\addedConcepts{behaves as if it
+ (\mbox{\ref{temp.constrained}}), a type, value, or template that has
+ an established archetype (described below)
+behaves as if it
were its archetype. \mbox{\enternote} this substitution of
archetypes (which are not dependent) for their corresponding
types, templates, or values (which would be dependent in an
@@ -5840,7 +5746,7 @@
archetype is ill-formed. An archetype is committed when:}
\begin{itemize}
\additemConcepts{the definition of the archetype is required,}
-\additemCC{the completeness of a type archetype might affect the semantics of the program, or}
+\additemConcepts{the completeness of a type archetype might affect the semantics of the program, or}
\additemConcepts{name lookup finds an associated function with a parameter that uses
a type that aliases the archetype.}
\end{itemize}
@@ -5895,7 +5801,7 @@
\begin{itemize}
\additemConcepts{an object type ([intro.object]), if the template
contains the requirement \mbox{\tcode{std::ObjectType<T>}},}
-\additemCC{a function type (\mbox{\ref{dcl.fct}}), if the template
+\additemConcepts{a function type (\mbox{\ref{dcl.fct}}), if the template
contains the requirement \mbox{\tcode{std::FunctionType<T>}},}
\additemConcepts{a class type (clause~\mbox{\ref{class}}), if the
template contains the requirement
@@ -5916,13 +5822,13 @@
\additemConcepts{a scalar type (\mbox{\ref{basic.types}}), if the
template contains the requirement
\mbox{\tcode{std::ScalarType<T>}},}
-\additemCC{an arithmetic type (\mbox{\ref{basic.fundamental}}), if the
+\additemConcepts{an arithmetic type (\mbox{\ref{basic.fundamental}}), if the
template contains the requirement
\mbox{\tcode{std::ArithmeticType<T>}},}
\additemConcepts{an integral type (\mbox{\ref{basic.fundamental}}), if the
template contains the requirement
\mbox{\tcode{std::IntegralType<T>}},}
-\additemCC{a floating point type (\mbox{\ref{basic.fundamental}}), if the
+\additemConcepts{a floating point type (\mbox{\ref{basic.fundamental}}), if the
template contains the requirement
\mbox{\tcode{std::FloatingPointType<T>}}, and}
\additemConcepts{an enumeration type (\mbox{\ref{dcl.enum}}), if the template
@@ -6149,8 +6055,8 @@
map, and its definition is used to resolve name
lookup into
requirements scope (\mbox{\ref{basic.scope.req}}) and satisfy the
-requirements of templates used inside the constrained context.}
-\addedCC{When the definition of a concept map archetype is required,
+requirements of templates used inside the constrained context.
+When the definition of a concept map archetype is required,
it will be synthesized from the definition of its corresponding
concept (\mbox{\ref{concept.map}}). An implementation shall not
define a concept map archetype
@@ -6183,10 +6089,9 @@
\rSec2[temp.constrained.set]{Candidate sets}
\pnum
\addedConcepts{A \mbox{\techterm{candidate set}} is a set containing
- functions and function templates}
-\addedCC{that is determined by a \mbox{\techterm{seed}} (defined below).}
-\changedCCC{that}{A candidate set}
-\addedConcepts{is defined in a constrained
+ functions and function templates
+that is determined by a \mbox{\techterm{seed}} (defined below).
+A candidate set is defined in a constrained
context (a \mbox{\techterm{retained}} \mbox{\techterm{candidate
set}},~\mbox{\ref{temp.constrained.inst}}) or as the result of
satisfying an associated function requirement in a concept map (an
@@ -6290,18 +6195,16 @@
\addedConcepts{In the instantiation of a constrained template, a call
to a function that resolves to an associated
function in a concept map archetype (\mbox{\ref{temp.archetype}})
- will be instantiated} \changedCCC{as a call to}{using}
-\addedConcepts{the associated function candidate set
+ will be instantiated using the associated function candidate set
(\mbox{\ref{temp.constrained.set}}) that satisfies the
corresponding associated function requirement in the concept map
- that replaces the concept map archetype.}
-\addedCC{The instantiated form depends on the seed of the associated
+ that replaces the concept map archetype.
+The instantiated form depends on the seed of the associated
function candidate set and the syntactic form that resulted in the
call in the constrained template:}
\begin{itemize}
-\additemCC{if the seed is a function, the instantiated form is a call
- to the associated function candidate set.}
-\addedConcepts{\mbox{\enterexample}}
+\additemConcepts{if the seed is a function, the instantiated form is a call
+ to the associated function candidate set. \mbox{\enterexample}}
\begin{codeblock}
concept F<typename T> {
T::T();
@@ -6326,11 +6229,11 @@
\end{codeblock}
\addedConcepts{\exitexample}
-\additemCC{if the seed is a \mbox{\techterm{pseudo-destructor-name}},
+\additemConcepts{if the seed is a \mbox{\techterm{pseudo-destructor-name}},
the instantiated form is a pseudo destructor call
(\mbox{\ref{expr.pseudo}}).}
-\additemCC{if the seed is the initialization of an object, the
+\additemConcepts{if the seed is the initialization of an object, the
instantiated form is the appropriate kind of initialization (or no
initialization) based on
the syntactic form in the constrained template. \enterexample}
@@ -6347,25 +6250,16 @@
template void f<int>(); // \tcode{t1} is not initialized, \tcode{t2} is value-initialized
\end{codeblock}
-\addedCC{\exitexample}
+\addedConcepts{\exitexample}
\end{itemize}
\pnum
-\addedConcepts{A use of a function template}
-\changedCCC{specialization}{instantiation}
-\addedConcepts{in a constrained
- template instantiates to a reference to that function template}
- \changedCCC{specialization}{instantiation}\addedConcepts{'s retained
- candidate set. The
+\addedConcepts{A use of a function template instantiation in a constrained
+ template instantiates to a reference to that function template
+ instantiation's retained candidate set. The
\mbox{\techterm{retained candidate set}} is a candidate set
- (\mbox{\ref{temp.constrained.set}}) whose seed is}
-\removedCCC{determined by}
-\addedConcepts{the
- function template} \changedCCC{specialization}{instantiation.}\removedCCC{from the
- definition of the
- constrained template, after substitution of the constrained
- template's template arguments for their corresponding template
- parameters.} \addedConcepts{\mbox{\enterexample}}
+ (\mbox{\ref{temp.constrained.set}}) whose seed is the
+ function template instantiation. \mbox{\enterexample}}
\begin{codeblock}
concept InputIterator<typename Iter> {
typename difference_type;
Boost-Commit list run by bdawes at acm.org, david.abrahams at rcn.com, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk