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Macro BOOST_SCOPE_EXIT_ID

BOOST_SCOPE_EXIT_ID — This macro allows to expand multiple scope exit declarations on the same line.

Synopsis

// In header: <boost/scope_exit.hpp>

BOOST_SCOPE_EXIT_ID(id, capture_list)

Description

This macro is equivalent to BOOST_SCOPE_EXIT but it can be expanded multiple times on the same line if different identifiers id are provided for each expansion (see BOOST_SCOPE_EXIT for more information).

Parameters:

id A unique identifier token which can be concatenated by the preprocessor (__LINE__, scope_exit_number_1_on_line_123, a combination of alphanumeric tokens, etc).
capture_list Same as the capture_list parameter of the BOOST_SCOPE_EXIT macro.

Note: This macro can be useful when the scope exit macros are expanded within user-defined macros (because nested macros expand on the same line). On some compilers (e.g., MSVC which supports the non standard __COUNTER__ macro) it might not be necessary to use this macro but the use of this macro is always necessary to ensure portability when expanding multiple scope exit declarations on the same line.

See: Tutorial section, BOOST_SCOPE_EXIT, BOOST_SCOPE_EXIT_END_ID, BOOST_SCOPE_EXIT_ALL_ID, BOOST_SCOPE_EXIT_ID_TPL.


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