Boost C++ Libraries

Parse a buffer containing all or part of a complete JSON text.

Synopsis

std::size_t
write_some(
    char const* data,
    std::size_t size);

Description

This function parses JSON text contained in the specified character buffer. If parsing completes, any additional characters past the end of the complete JSON text are ignored. The function returns the actual number of characters parsed, which may be less than the size of the input. This allows parsing of a buffer containing multiple individual JSON texts or containing different protocol data.

Example

stream_parser p;                                // construct a parser
std::size_t n;                                  // number of characters used
n = p.write_some( "[1,2" );                     // parse the first part of the JSON text
assert( n == 4 );                               // all characters consumed
n = p.write_some( "3,4] null" );                // parse the rest of the JSON text
assert( n == 5 );                               // only some characters consumed
value jv = p.release();                         // take ownership of the value

Remarks

To indicate there are no more character buffers, such as when done returns false after writing, call finish.

Complexity

Linear in size.

Exception Safety

Basic guarantee. Calls to memory_resource::allocate may throw. Upon error or exception, subsequent calls will fail until reset is called to parse a new JSON text.

Return Value

The number of characters consumed from the buffer.

Parameters

Exceptions