result_for

Helper trait that returns boost::system::result

Synopsis

Defined in header <boost/json/result_for.hpp>.

template<
    class T1,
    class T2>
struct result_for;

Description

The primary template is an incomplete type. The library provides a partial specialisation result_for<T1, value>, that has nested type alias type that aliases the type result<T1>.

The purpose of this trait is to let users provide non-throwing conversions for their types without creating a physical dependency on Boost.Json. For example:

namespace boost
{
namespace json
{

template<class T>
struct value_to_tag;

template<class T1, class T2>
struct result_for;
}
}

namespace mine
{
    class my_class;
    ...
    template<class JsonValue>
    boost::json::result_for<my_class, JsonValue>
    tag_invoke(boost::json::try_value_to_tag<my_class>, const JsonValue& jv)
    { ... }
}

See Also

try_value_to, try_value_to_tag

Convenience header <boost/json.hpp>.

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