The read_at function is a composed operation that reads a certain amount of data at the specified offset before returning.

Attempt to read a certain amount of data at the specified offset before returning.

template<
    typename SyncRandomAccessReadDevice,
    typename MutableBufferSequence>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    const MutableBufferSequence & buffers);
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template<
    typename SyncRandomAccessReadDevice,
    typename MutableBufferSequence>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    const MutableBufferSequence & buffers,
    boost::system::error_code & ec);
  » more...

template<
    typename SyncRandomAccessReadDevice,
    typename MutableBufferSequence,
    typename CompletionCondition>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    const MutableBufferSequence & buffers,
    CompletionCondition completion_condition);
  » more...

template<
    typename SyncRandomAccessReadDevice,
    typename MutableBufferSequence,
    typename CompletionCondition>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    const MutableBufferSequence & buffers,
    CompletionCondition completion_condition,
    boost::system::error_code & ec);
  » more...

template<
    typename SyncRandomAccessReadDevice,
    typename Allocator>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    basic_streambuf< Allocator > & b);
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template<
    typename SyncRandomAccessReadDevice,
    typename Allocator>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    basic_streambuf< Allocator > & b,
    boost::system::error_code & ec);
  » more...

template<
    typename SyncRandomAccessReadDevice,
    typename Allocator,
    typename CompletionCondition>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    basic_streambuf< Allocator > & b,
    CompletionCondition completion_condition);
  » more...

template<
    typename SyncRandomAccessReadDevice,
    typename Allocator,
    typename CompletionCondition>
std::size_t read_at(
    SyncRandomAccessReadDevice & d,
    uint64_t offset,
    basic_streambuf< Allocator > & b,
    CompletionCondition completion_condition,
    boost::system::error_code & ec);
  » more...

Requirements

Header: boost/asio/impl/read_at.hpp

Convenience header: boost/asio.hpp