Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Boost
C++ Libraries
...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
Convert an object of type T
to value.
Defined in header <boost/json/value_from.hpp>
template<
class T>
void
value_from(
T&& t,
value& jv);
This function attempts to convert an object of type T
to value
using
value's
constructors,
tag_invoke.
Out of the box the function supports types satisfying SequenceContainer,
arrays, arithmetic types, bool,
std::tuple, std::pair,
std::variant, std::optional,
std::monostate, and std::nullopt_t.
Conversion of other types is done by calling an overload of tag_invoke found by argument-dependent
lookup. Its signature should be similar to:
void tag_invoke( value_from_tag, value&, T );
Strong guarantee.
|
Type |
Description |
|---|---|
|
|
The type of the object to convert. |
|
Name |
Description |
|---|---|
|
|
The object to convert. |
|
|
|
value_from_tag,
value_to,
tag_invoke:
A general pattern for supporting customisable functions
Convenience header <boost/json.hpp>