nlohmann::basic_json::operator>=¶
// until C++20
bool operator>=(const_reference lhs, const_reference rhs) noexcept; // (1)
template<typename ScalarType>
bool operator>=(const_reference lhs, const ScalarType rhs) noexcept; // (2)
template<typename ScalarType>
bool operator>=(ScalarType lhs, const const_reference rhs) noexcept; // (2)
-
Compares whether one JSON value
lhs
is greater than or equal to another JSON valuerhs
according to the following rules:- The comparison always yields
false
if (1) either operand is discarded, or (2) either operand isNaN
and the other operand is eitherNaN
or any other number. - Otherwise, returns the result of
!(lhs < rhs)
(see operator<).
- The comparison always yields
-
Compares whether a JSON value is greater than or equal to a scalar or a scalar is greater than or equal to a JSON value by converting the scalar to a JSON value and comparing both JSON values according to 1.
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 or equal to rhs
Exception safety¶
No-throw guarantee: this function never throws exceptions.
Complexity¶
Linear.
Notes¶
Comparing NaN
NaN
values are unordered within the domain of numbers. The following comparisons all yield false
: 1. Comparing a NaN
with itself. 2. Comparing a NaN
with another NaN
. 3. Comparing a NaN
and any other number.
Operator overload resolution
Since C++20 overload resolution will consider the rewritten candidate generated from operator<=>
.
Examples¶
Example
The example demonstrates comparing several JSON types.
#include <iostream>
#include <nlohmann/json.hpp>
using json = nlohmann::json;
int main()
{
// create several JSON values
json array_1 = {1, 2, 3};
json array_2 = {1, 2, 4};
json object_1 = {{"A", "a"}, {"B", "b"}};
json object_2 = {{"B", "b"}, {"A", "a"}};
json number_1 = 17;
json number_2 = 17.0000000000001L;
json string_1 = "foo";
json string_2 = "bar";
// output values and comparisons
std::cout << std::boolalpha;
std::cout << array_1 << " >= " << array_2 << " " << (array_1 >= array_2) << '\n';
std::cout << object_1 << " >= " << object_2 << " " << (object_1 >= object_2) << '\n';
std::cout << number_1 << " >= " << number_2 << " " << (number_1 >= number_2) << '\n';
std::cout << string_1 << " >= " << string_2 << " " << (string_1 >= string_2) << '\n';
}
Output:
[1,2,3] >= [1,2,4] false
{"A":"a","B":"b"} >= {"A":"a","B":"b"} true
17 >= 17.0000000000001 false
"foo" >= "bar" true
See also¶
- operator<=> comparison: 3-way
Version history¶
- Added in version 1.0.0. Conditionally removed since C++20 in version 3.11.0.
- Added in version 1.0.0. Conditionally removed since C++20 in version 3.11.0.