LWG2139 What is a user-defined type?

Some of the underlying text has changed, and the edits
were applied to the changed text.
There is one remaining appearance of 'user-defined type' in
[namespace.std], which was not changed.

Author: jensmaurer

source/diagnostics.tex

@@ -918,7 +918,7 @@
 
 \pnum
 The \tcode{is_error_code_enum} and \tcode{is_error_condition_enum} may be
-specialized for user-defined types to indicate that such types are eligible
+specialized for program-defined types to indicate that such types are eligible
 for \tcode{class error_code} and \tcode{class error_condition} automatic
 conversions, respectively.
 

source/lib-intro.tex

@@ -283,6 +283,24 @@
 member functions\iref{class.this}.
 \end{defnote}
 
+\definition{program-defined specialization}{defns.prog.def.spec}
+\indexdefn{specialization!program-defined}%
+explicit template specialization or partial specialization
+that is not part of the C++ standard library and
+not defined by the implementation
+
+\definition{program-defined type}{defns.prog.def.type}
+\indexdefn{type!program-defined}%
+class type or enumeration type
+that is not part of the C++ standard library and
+not defined by the implementation,
+or an instantiation of a program-defined specialization
+
+\begin{defnote}
+Types defined by the implementation include
+extensions\iref{intro.compliance} and internal types used by the library.
+\end{defnote}
+
 \definition{referenceable type}{defns.referenceable}
 \indexdefn{type!referenceable}%
 type that is either an
@@ -2169,7 +2187,7 @@
 to namespace
 \tcode{std} provided that
 (a) the added declaration
-depends on at least one user-defined type
+depends on at least one program-defined type
 and
 (b) the specialization meets the standard library requirements
 for the original template.\footnote{Any
@@ -2202,7 +2220,7 @@
 A program may explicitly instantiate
 a class template defined in the standard library
 only if the declaration
-(a) depends on the name of at least one user-defined type
+(a) depends on the name of at least one program-defined type
 and
 (b) the instantiation meets the standard library requirements for the
 original template.

source/locales.tex

@@ -1908,7 +1908,7 @@
 Specializations on
 \tcode{mbstate_t}
 perform conversion between encodings known to the library implementer.
-Other encodings can be converted by specializing on a user-defined
+Other encodings can be converted by specializing on a program-defined
 \tcode{stateT}
 type.
 Objects of type

source/regex.tex

@@ -3651,7 +3651,7 @@
 
 \pnum
 \begin{note} This means that a compiler may call an
-implementation-specific search function, in which case a user-defined
+implementation-specific search function, in which case a program-defined
 specialization of \tcode{regex_search} will not be
 called. \end{note}
 \end{itemdescr}

source/utilities.tex

@@ -7150,7 +7150,7 @@
 is valid and denotes a type\iref{temp.deduct} and
 \tcode{is_convertible_v<Alloc, T::allocator_type> != false}, otherwise it shall be
 derived from \tcode{false_type}. A program may specialize this template to derive from
-\tcode{true_type} for a user-defined type \tcode{T} that does not have a nested
+\tcode{true_type} for a program-defined type \tcode{T} that does not have a nested
 \tcode{allocator_type} but nonetheless can be constructed with an allocator where
 either:
 
@@ -14281,7 +14281,7 @@
 shall provide a definition that has a base characteristic of
 \tcode{true_type} if \tcode{T} is a type returned from \tcode{bind},
 otherwise it shall have a base characteristic of \tcode{false_type}.
-A program may specialize this template for a user-defined type \tcode{T}
+A program may specialize this template for a program-defined type \tcode{T}
 to have a base characteristic of \tcode{true_type} to indicate that
 \tcode{T} should be treated as a subexpression in a \tcode{bind} call.
 
@@ -14306,7 +14306,7 @@
 \tcode{integral_constant<int, \placeholder{J}>} if \tcode{T} is the type of
 \tcode{std::placeholders::_\placeholder{J}}, otherwise it shall have a
 base characteristic of \tcode{integral_constant<int, 0>}. A program
-may specialize this template for a user-defined type \tcode{T} to
+may specialize this template for a program-defined type \tcode{T} to
 have a base characteristic of \tcode{integral_constant<int, N>}
 with \tcode{N > 0} to indicate that \tcode{T} should be
 treated as a placeholder type.
@@ -15271,7 +15271,7 @@
 \item satisfy the requirement that the expression \tcode{h(k)}, where \tcode{h}
 is an object of type \tcode{hash<Key>} and \tcode{k} is an object of type
 \tcode{Key}, shall not throw an exception unless \tcode{hash<Key>} is a
-user-defined specialization that depends on at least one user-defined type.
+program-defined specialization that depends on at least one program-defined type.
 \end{itemize}
 
 \rSec1[meta]{Metaprogramming and type traits}