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nlohmann
62 lines
1.1 KiB
Markdown
62 lines
1.1 KiB
Markdown
# nlohmann::json_pointer::empty
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```
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bool empty() const noexcept;
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```
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Return whether the pointer points to the root document.
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## Return value
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`true` iff the JSON pointer points to the root document.
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## Exception safety
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No-throw guarantee: this function never throws exceptions.
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## Complexity
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Constant.
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## Examples
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Example
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The example shows the result of `empty` for different JSON Pointers.
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```
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#include <iostream>
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#include <nlohmann/json.hpp>
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using json = nlohmann::json;
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int main()
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{
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// different JSON Pointers
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json::json_pointer ptr0;
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json::json_pointer ptr1("");
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json::json_pointer ptr2("/foo");
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json::json_pointer ptr3("/foo/0");
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// call empty()
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std::cout << std::boolalpha
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<< "\"" << ptr0 << "\": " << ptr0.empty() << '\n'
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<< "\"" << ptr1 << "\": " << ptr1.empty() << '\n'
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<< "\"" << ptr2 << "\": " << ptr2.empty() << '\n'
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<< "\"" << ptr3 << "\": " << ptr3.empty() << std::endl;
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}
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```
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Output:
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```
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"": true
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"": true
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"/foo": false
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"/foo/0": false
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```
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## Version history
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Added in version 3.6.0.
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