2020-08-12 19:41:59 +08:00
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# basic_json::value_t
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```cpp
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enum class value_t : std::uint8_t {
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null,
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object,
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array,
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string,
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boolean,
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number_integer,
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number_unsigned,
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number_float,
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binary,
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discarded
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};
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```
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2020-08-12 20:29:25 +08:00
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This enumeration collects the different JSON types. It is internally used to distinguish the stored values, and the
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functions [`is_null`](is_null.md), [`is_object`](is_object.md), [`is_array`](is_array.md), [`is_string`](is_string.md),
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[`is_boolean`](is_boolean.md), [`is_number`](is_number.md) (with [`is_number_integer`](is_number_integer.md),
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2020-08-12 19:41:59 +08:00
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[`is_number_unsigned`](is_number_unsigned.md), and [`is_number_float`](is_number_float.md)),
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[`is_discarded`](is_discarded.md), [`is_binary`](is_binary.md), [`is_primitive`](is_primitive.md), and
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[`is_structured`](is_structured.md) rely on it.
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## Note
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2020-08-12 20:29:25 +08:00
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There are three enumeration entries (number_integer, number_unsigned, and number_float), because the library
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distinguishes these three types for numbers: [`number_unsigned_t`](number_unsigned_t.md) is used for unsigned integers,
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[`number_integer_t`](number_integer_t.md) is used for signed integers, and [`number_float_t`](number_float_t.md) is used
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for floating-point numbers or to approximate integers which do not fit in the limits of their respective type.
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2020-08-12 19:41:59 +08:00
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## Version history
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- Added in version 1.0.0.
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- Added unsigned integer type in version 2.0.0.
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- Added binary type in version 3.8.0.
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