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* 🔥 consolidate documentation
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2021-12-29 13:41:01 +01:00

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nlohmann::basic_json::get_ptr

template<typename PointerType>
PointerType get_ptr() noexcept;

template<typename PointerType>
constexpr const PointerType get_ptr() const noexcept;

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

Template parameters

PointerType: pointer type; must be a pointer to array_t, object_t, string_t, boolean_t, number_integer_t, or number_unsigned_t, number_float_t, or binary_t. Other types will not compile.

Return value

pointer to the internally stored JSON value if the requested pointer type fits to the JSON value; #!cpp nullptr otherwise

Exception safety

No-throw guarantee: this function never throws exceptions.

Complexity

Constant.

Notes

!!! warning

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

Examples

??? 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 `#!cpp nullptr` is returned if the value and the requested pointer type does not match.

```cpp
--8<-- "examples/get_ptr.cpp"
```

Output:

```json
--8<-- "examples/get_ptr.output"
```

Version history

Added in version 1.0.0.
Extended to binary types in version 3.8.0.

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