Struct template value

Boost C++ Libraries

Struct template value

boost::xpressive::value — value<> is a lazy wrapper for a value that can be used in xpressive semantic actions.

Synopsis

// In header: <boost/xpressive/regex_actions.hpp>

template<typename T> 
struct value : public  {

  // public member functions
  ();
  ();
   ();
   () ;
};

Description

Below is an example that shows where value<> is useful.

 ;
    // Use val() to hold the shared_ptr by value:
      [ ++*(

In the above code, xpressive::val() is a function that returns a value<> object. Had val() not been used here, the operation ++*pi would have been evaluated eagerly once, instead of lazily when the regex match happens.

Template Parameters

```
typename T
```
The type of the value to store.

`value` public member functions

```
();
```
Store a default-constructed T.
```
( t);
```
Store a copy of t.

Parameters:

t

The initial value.
```
 ();
```
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
```
 () ;
```
Fetch the stored value.