null_category

Conversion category for null types.

Synopsis

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

struct null_category;

Description

Null types are represented in JSON as the null literal.

By default only the type std::nullptr_t is considered a null type.

Users can specialize conversion_category_for for their own types if they want them to be treated as nulls. For example:

namespace boost {
namespace json {

template <>
struct conversion_category_for<your::null>
{
    using type = null_category;
};

} // namespace boost
} // namespace json

Matching Types

std::nullptr_t.

Convenience header <boost/json.hpp>.

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