__basic_json
allocator_type
array
array_t
at
at
at
at
back
back
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
basic_json
begin
begin
boolean_t
cbegin
cend
clear
const_pointer
const_reference
count
crbegin
crend
difference_type
dump
empty
end
end
erase
erase
erase
erase
find
find
front
front
get
get
get_allocator
get_ptr
is_array
is_boolean
is_discarded
is_null
is_number
is_number_float
is_number_integer
is_object
is_string
list_init_t
max_size
number_float_t
number_integer_t
object
object_t
operator value_t
operator ValueType
operator!=
operator+=
operator+=
operator+=
operator<
operator<
operator<<
operator<<
operator<=
operator=
operator==
operator>
operator>=
operator>>
operator>>
operator[]
operator[]
operator[]
operator[]
operator[]
operator[]
parse
parse
parse_event_t
parser_callback_t
pointer
push_back
push_back
push_back
rbegin
rbegin
reference
rend
rend
size
size_type
string_t
swap
swap
swap
swap
type
value_t
value_type
~basic_json

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 = int64_t, class NumberFloatType = double, template< typename U > class AllocatorType = std::allocator>
template<typename PointerType , typename std::enable_if< std::is_pointer< PointerType >::value, int >::type = 0>

PointerType nlohmann::basic_json::get_ptr | ( |  | ) |

inline

Implict pointer access to the internally stored JSON value. No copies are made.

Warning
  Writing data to the pointee of the result yields an undefined state.

Template Parameters

  PointerType | pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, or number_float_t.

Returns
  pointer to the internally stored JSON value if the requested pointer type PointerType fits to the JSON value; `nullptr` otherwise

Complexity
  Constant.

Example
  The example below shows how pointers to internal values of a JSON value can be requested. Note that no type conversions are made and a `nullptr` is returned if the value and the requested pointer type does not match.
  #include <json.hpp>
  using namespace nlohmann;
  int main()
  {
  // create a JSON boolean
  json value = 17;
  // explicitly getting pointers
  auto p1 = value.get_ptr<const json::number_integer_t*>();
  auto p2 = value.get_ptr<json::number_integer_t*>();
  auto p3 = value.get_ptr<json::number_integer_t* const>();
  auto p4 = value.get_ptr<const json::number_integer_t* const>();
  auto p5 = value.get_ptr<json::number_float_t*>();
  // print the pointees
  std::cout << *p1 << ' ' << *p2 << ' ' << *p3 << ' ' << *p4 << '\n';
  std::cout << std::boolalpha << (p5 == nullptr) << '\n';
  }
  nlohmann::basic_json
  a class to store JSON values
  Definition: json.hpp:121
  nlohmann
  namespace for Niels Lohmann
  Definition: json.hpp:56
  nlohmann::basic_json::number_integer_t
  NumberIntegerType number_integer_t
  a type for a number (integer)
  Definition: json.hpp:195
  nlohmann::basic_json::number_float_t
  NumberFloatType number_float_t
  a type for a number (floating-point)
  Definition: json.hpp:197
  nlohmann::basic_json::get_ptr
  PointerType get_ptr()
  get a pointer value (implicit)
  Definition: json.hpp:1933
  Output:

      17 17 17 17
      true

  The example code above can be translated with

      g++ -std=c++11 -Isrc doc/examples/get_ptr.cpp -o get_ptr

  .