class template
<locale>
std::num_get
template <class charT, class InputIterator = istreambuf_iterator<charT> > class num_get;
Facet to parse numeric values
The num_get standard facet parses sequences of character to obtain numerical values. Its member get is called by standard input streams (such as istream) to obtain formatted numerical values with the extraction operator (operator>>).
The num_get 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 num_get class template (as part of the numeric category):
| facets in locale objects | notes |
|---|
num_get<char> | narrow characters (used by istream) |
num_get<wchar_t> | wide characters (used by wistream) |
Template parameters
- charT
- Character type: the type of the characters in the sequence to interpret.
Aliased as member char_type.
- InputIterator
- Input iterator type that points to the elements in the character sequence to interpret.
Defaults to istreambuf_iterator, which is an iterator that can be implicitly converted from basic_istream objects.
Aliased as member iter_type.
Member types
| member type | definition | description |
|---|
| char_type | The first template parameter (charT) | Character type |
| iter_type | The second template parameter (InputIterator) | Iterator type.
Defaults to istreambuf_iterator<charT> |
Member constants
The class contains a public static constant of type locale::id that uniquely identifies facets with num_get semantics.
Public member functions
- (constructor)
- num_get constructor (public member function
)
- get
- Get numeric value (public member function
)
Virtual protected member functions
- do_get
- Get numeric value [virtual] (protected virtual member function
)
- (destructor)
- num_get destructor (protected member function
)
Specializations
At least the following specializations and partial specializations of this template are provided in all library implementations:
| specialization |
|---|
num_get<char> |
num_get<wchar_t> |
template <class InputIterator> num_get<char,InputIterator> |
template <class InputIterator> num_get<wchar_t,InputIterator> |
Where InputIterator shall be a type that satisfies the requirements of an input iterator able to iterate over elements of the specified character type.