get_impl() [2/6]

template<template< typename U, typename V, typename... Args > class ObjectType = std::map, template< typename U, typename... Args > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator, template< typename T, typename SFINAE=void > class JSONSerializer = adl_serializer, class BinaryType = std::vector<std::uint8_t>>

template<typename ValueType , detail::enable_if_t< detail::is_default_constructible< ValueType >::value &&detail::has_from_json< basic_json_t, ValueType >::value, int > = 0>

ValueType nlohmann::basic_json< ObjectType, ArrayType, StringType, BooleanType, NumberIntegerType, NumberUnsignedType, NumberFloatType, AllocatorType, JSONSerializer, BinaryType >::get_impl ( detail::priority_tag< 0 >  ) const

inlineprivatenoexcept

get a value (explicit)

Explicit type conversion between the JSON value and a compatible value which is CopyConstructible and DefaultConstructible. The value is converted by calling the json_serializer<ValueType> from_json() method.

The function is equivalent to executing

ValueType ret;
JSONSerializer<ValueType>::from_json(*this, ret);
return ret;

This overloads is chosen if:

• ValueType is not basic_json,
• json_serializer<ValueType> has a from_json() method of the form void from_json(const basic_json&, ValueType&), and
• json_serializer<ValueType> does not have a from_json() method of the form ValueType from_json(const basic_json&)

Template Parameters

ValueType

the returned value type

Returns

copy of the JSON value, converted to ValueType

Exceptions

what	json_serializer<ValueType> from_json() method throws

@liveexample{The example below shows several conversions from JSON values to other types. There a few things to note: (1) Floating-point numbers can be converted to integers\, (2) A JSON array can be converted to a standard std::vector<short>\, (3) A JSON object can be converted to C++ associative containers such as std::unordered_map<std::string\, json>.,get__ValueType_const}

Since

version 2.1.0

Definition at line 20769 of file json.hpp.

    {
        ValueType ret{};
        JSONSerializer<ValueType>::from_json(*this, ret);
        return ret;
    }