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-rw-r--r--gcc/doc/extend.texi119
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diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index d01e5fa..ccdc995 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -10675,6 +10675,7 @@ Predefined Macros,cpp,The GNU C Preprocessor}).
method denoted by a @samp{->*} or @samp{.*} expression.
* C++ Attributes:: Variable, function, and type attributes for C++ only.
* Namespace Association:: Strong using-directives for namespace association.
+* Type Traits:: Compiler support for type traits
* Java Exceptions:: Tweaking exception handling to work with Java.
* Deprecated Features:: Things will disappear from g++.
* Backwards Compatibility:: Compatibilities with earlier definitions of C++.
@@ -11232,6 +11233,124 @@ int main()
@}
@end smallexample
+@node Type Traits
+@section Type Traits
+
+The C++ front-end implements syntactic extensions that allow to
+determine at compile time various characteristics of a type (or of a
+pair of types).
+
+@table @code
+@item __has_nothrow_assign (type)
+If @code{__has_trivial_assign (type)} is true then the trait is true, else if
+@code{type} is a cv class or union type with copy assignment operators that
+are known not to throw an exception then the trait is true, else it is false.
+If @code{type} is const qualified, any copy assignment operator must
+be both known not to throw an exception, and const qualified, for the
+trait to be true. Requires: @code{type} shall be a complete type, an
+array type of unknown bound, or is a @code{void} type.
+
+@item __has_nothrow_copy (type)
+If @code{__has_trivial_copy (type)} is true then the trait is true, else if
+@code{type} is a cv class or union type with copy constructors that
+are known not to throw an exception then the trait is true, else it is false.
+Requires: @code{type} shall be a complete type, an array type of
+unknown bound, or is a @code{void} type.
+
+@item __has_nothrow_constructor (type)
+If @code{__has_trivial_constructor (type)} is true then the trait is
+true, else if @code{type} is a cv class or union type (or array
+thereof) with a default constructor that is known not to throw an
+exception then the trait is true, else it is false. Requires:
+@code{type} shall be a complete type, an array type of unknown bound,
+or is a @code{void} type.
+
+@item __has_trivial_assign (type)
+If @code{type} is const qualified or is a reference type then the trait is
+false. Otherwise if @code{__is_pod (type)} is true then the trait is
+true, else if @code{type} is a cv class or union type with a trivial
+copy assignment ([class.copy]) then the trait is true, else it is
+false. Requires: @code{type} shall be a complete type, an array type
+of unknown bound, or is a @code{void} type.
+
+@item __has_trivial_copy (type)
+If @code{__is_pod (type)} is true or @code{type} is a reference type
+then the trait is true, else if @code{type} is a cv class or union type
+with a trivial copy constructor ([class.copy]) then the trait
+is true, else it is false. Requires: @code{type} shall be a complete
+type, an array type of unknown bound, or is a @code{void} type.
+
+@item __has_trivial_constructor (type)
+If @code{__is_pod (type)} is true then the trait is true, else if
+@code{type} is a cv class or union type (or array thereof) with a
+trivial default constructor ([class.ctor]) then the trait is true,
+else it is false. Requires: @code{type} shall be a complete type, an
+array type of unknown bound, or is a @code{void} type.
+
+@item __has_trivial_destructor (type)
+If @code{__is_pod (type)} is true or @code{type} is a reference type then
+the trait is true, else if @code{type} is a cv class or union type (or
+array thereof) with a trivial destructor ([class.dtor]) then the trait
+is true, else it is false. Requires: @code{type} shall be a complete
+type, an array type of unknown bound, or is a @code{void} type.
+
+@item __has_virtual_destructor (type)
+If @code{type} is a class type with a virtual destructor
+([class.dtor]) then the trait is true, else it is false. Requires:
+@code{type} shall be a complete type, an array type of unknown bound,
+or is a @code{void} type.
+
+@item __is_abstract (type)
+If @code{type} is an abstract class ([class.abstract]) then the trait
+is true, else it is false. Requires: @code{type} shall be a complete
+type, an array type of unknown bound, or is a @code{void} type.
+
+@item __is_base_of (base_type, derived_type)
+If @code{base_type} is a base class of @code{derived_type}
+([class.derived]) then the trait is true, otherwise it is false.
+Top-level cv qualifications of @code{base_type} and
+@code{derived_type} are ignored. For the purposes of this trait, a
+class type is considered is own base. Requires: if @code{__is_class
+(base_type)} and @code{__is_class (derived_type)} are true and
+@code{base_type} and @code{derived_type} are not the same type
+(disregarding cv-qualifiers), @code{derived_type} shall be a complete
+type. Diagnostic is produced if this requirement is not met.
+
+@item __is_class (type)
+If @code{type} is a cv class type, and not a union type
+([basic.compound]) the the trait is true, else it is false.
+
+@item __is_empty (type)
+If @code{__is_class (type)} is false then the trait is false.
+Otherwise @code{type} is considered empty if and only if: @code{type}
+has no non-static data members, or all non-static data members, if
+any, are bit-fields of lenght 0, and @code{type} has no virtual
+members, and @code{type} has no virtual base classes, and @code{type}
+has no base classes @code{base_type} for which
+@code{__is_empty (base_type)} is false. Requires: @code{type} shall
+be a complete type, an array type of unknown bound, or is a
+@code{void} type.
+
+@item __is_enum (type)
+If @code{type} is a cv enumeration type ([basic.compound]) the the trait is
+true, else it is false.
+
+@item __is_pod (type)
+If @code{type} is a cv POD type ([basic.types]) then the trait is true,
+else it is false. Requires: @code{type} shall be a complete type,
+an array type of unknown bound, or is a @code{void} type.
+
+@item __is_polymorphic (type)
+If @code{type} is a polymorphic class ([class.virtual]) then the trait
+is true, else it is false. Requires: @code{type} shall be a complete
+type, an array type of unknown bound, or is a @code{void} type.
+
+@item __is_union (type)
+If @code{type} is a cv union type ([basic.compound]) the the trait is
+true, else it is false.
+
+@end table
+
@node Java Exceptions
@section Java Exceptions