operator>>

## `operator>>`

Parse `value` from an input stream.

### Synopsis

Defined in header <boost/json/value.hpp>.

    std::istream&
    operator>>(
        std::istream& is,
        value& jv);

### Description

This function parses JSON from an input stream into a `value`. If parsing fails, `std::ios_base::failbit` will be set for `is` and `jv` will be left unchanged. Regardless of whether `std::ios_base::skipws` flag is set on `is`, consumes whitespace before and after JSON, because whitespace is considered a part of JSON. Behaves as FormattedInputFunction.

| This operator cannot assume that the stream only contains a single JSON document, which may result in very underwhelming performance, if the stream isn’t cooperative. If you know that your input consists of a single JSON document, consider using `parse` function instead.

### Complexity

Linear in the size of JSON data.

### Exception Safety

Basic guarantee. Calls to `memory_resource::allocate` may throw. The stream may throw as configured by `std::ios::exceptions`.

### Return Value

Reference to `is`.

### Parameters

Name | Description
--- | ---
`is` | The input stream to parse from.
`jv` | The value to parse into.

### See Also

`parse`.

Convenience header <boost/json.hpp>

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