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◆ operator>> [2/2]
template<template< typename, typename, typename... > class ObjectType = std::map, template< typename, typename... > class ArrayType = std::vector, class StringType = std::string, class BooleanType = bool, class NumberIntegerType = std::int64_t, class NumberUnsignedType = std::uint64_t, class NumberFloatType = double, template< typename > class AllocatorType = std::allocator, template< typename, typename=void > class JSONSerializer = adl_serializer>
std::istream& operator>> |
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std::istream & |
i, |
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basic_json & |
j |
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friend |
Deserializes an input stream to a JSON value.
- Parameters
-
[in,out] | i | input stream to read a serialized JSON value from |
[in,out] | j | JSON value to write the deserialized input to |
- Exceptions
-
parse_error.101 | in case of an unexpected token |
parse_error.102 | if to_unicode fails or surrogate error |
parse_error.103 | if to_unicode fails |
- Complexity
- Linear in the length of the input. The parser is a predictive LL(1) parser.
- Note
- A UTF-8 byte order mark is silently ignored.
- Example
- The example below shows how a JSON value is constructed by reading a serialization from a stream.
12 "string": "Hello, world!", 13 "array": [1, 2, 3, 4, 5], 23 std::cout << std::setw(2) << j << '\n'; basic_json<> json default JSON class
Output (play with this example online): {
"array": [
1,
2,
3,
4,
5
],
"boolean": false,
"null": null,
"number": 23,
"string": "Hello, world!"
}
The example code above can be translated withg++ -std=c++11 -Isrc doc/examples/operator_deserialize.cpp -o operator_deserialize
- See also
- parse(std::istream&, const parser_callback_t) for a variant with a parser callback function to filter values while parsing
- Since
- version 1.0.0
Definition at line 13163 of file json.hpp.
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