WhisperCom/doc/mkdocs/docs/api/basic_json/operator_lt.md

74 lines
1.5 KiB
Markdown
Raw Normal View History

# basic_json::operator<
```cpp
bool operator<(const_reference lhs, const_reference rhs) noexcept,
template<typename ScalarType>
bool operator<(const_reference lhs, const ScalarType rhs) noexcept;
template<typename ScalarType>
bool operator<(ScalarType lhs, const const_reference rhs) noexcept;
```
Compares whether one JSON value `lhs` is less than another JSON value `rhs` according to the following rules:
- If `lhs` and `rhs` have the same type, the values are compared using the default `<` operator.
- Integer and floating-point numbers are automatically converted before comparison
- Discarded values a
- In case `lhs` and `rhs` have different types, the values are ignored and the order of the types is considered, which
is:
1. null
2. boolean
3. number (all types)
4. object
5. array
6. string
7. binary
For instance, any boolean value is considered less than any string.
## Template parameters
`ScalarType`
: a scalar type according to `std::is_scalar<ScalarType>::value`
## Parameters
`lhs` (in)
: first value to consider
`rhs` (in)
: second value to consider
## Return value
whether `lhs` is less than `rhs`
## Exception safety
No-throw guarantee: this function never throws exceptions.
## Complexity
Linear.
## Example
??? example
The example demonstrates comparing several JSON types.
```cpp
--8<-- "examples/operator__less.cpp"
```
Output:
```json
--8<-- "examples/operator__less.output"
```
## Version history
- Added in version 1.0.0.