class template
<locale>
std::messages
template <class charT> class messages;
Facet to access message catalogs
The messages standard facet is used to read individual strings from a message catalog.
The specifics on how messages are organized in a catalog depend on the library implementation.
The messages class template has a protected destructor: Programs shall only construct objects of derived classes, or use those installed in locale objects (through use_facet).
All standard locale objects support at least the following facet instantiations of the messages class template as part of the messages category:
| facets in locale objects | description |
|---|
messages<char> | narrow characters |
messages<wchar_t> | wide characters |
Template parameters
- charT
- Character type.
This is the type of characters for the returned messages.
Aliased as member char_type.
Member types
| member type | definition | description |
|---|
| char_type | The template parameter (charT) | Character type |
| string_type | basic_string<charT> | The basic_string instantiation for characters of type charT (such as string for char).
|
The class also inherits the catalog type from messages_base. This type is a mere alias (typedef) of a signed integer type.
Member constants
The class contains a public static constant of type locale::id that uniquely identifies facets with money_put semantics.
Public member functions
- (constructor)
- messages constructor (public member function)
- open
- Open message catalog (public member function
)
- get
- Get message from catalog (public member function
)
- close
- Closse message catalog (public member function
)
Virtual protected member functionss
The class defines the virtual protected members which implement the behavior by default of their respective public member functions:
- do_open
- Open message catalog [virtual] (protected virtual member function
)
- do_get
- Get message from catalog [virtual] (protected virtual member function
)
- do_close
- Close message catalog (protected virtual member function
)
Along with the class destructor:
- (destructor)
- messages destructor (protected member function
)
Specializations
At least the following specializations of this template are provided in all library implementations:
| specialization |
|---|
messages<char> |
messages<wchar_t> |