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◆ basic_json() [2/9]
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>
Create a null JSON value. It either takes a null pointer as parameter (explicitly creating null ) or no parameter (implicitly creating null ). The passed null pointer itself is not read – it is only used to choose the right constructor.
- Complexity\n Constant.
- Exception safety\n No-throw guarantee: this constructor never throws
- exceptions.
- Example\n The following code shows the constructor with and without a
- null pointer parameter.
14 std::cout << j1 << '\n' << j2 << '\n';
static basic_json array(std::initializer_list< basic_json > init=std::initializer_list< basic_json >()) explicitly create an array from an initializer list
a class to store JSON values
basic_json<> json default JSON class
Output (play with this example online):
null
null
The example code above can be translated with g++ -std=c++11 -Isrc doc/examples/basic_json__nullptr_t.cpp -o basic_json__nullptr_t
- Since
- version 1.0.0
Definition at line 1940 of file json.hpp.
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