libs/test/doc/testing_tools/boost_test_universal_macro.qbk
[/ / Copyright (c) 2015 Boost.Test contributors / / Distributed under the Boost Software License, Version 1.0. (See accompanying / file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) /] [section:boost_test_universal_macro BOOST_TEST: universal and general purpose assertions] The __UTF__ provides an almost unique interface to a great range of test-case scenarios, through the __BOOST_TEST__ macro. The general form of `BOOST_TEST` is the following: BOOST_TEST(statement); BOOST_TEST_<level>(statement, optional_modifiers) An example of use might be the following: [bt_example boost_test_macro_overview..BOOST_TEST overview..run-fail] The major features of this tool are: * a great flexibility for `statement` which may be almost anything: full expression composed by several operations are supported and handled, * an extended reporting capability in case of failure: not only `BOOST_TEST` reports the location of the failure and a copy of `statement` itself, but also the values of the operands that permits a rapid identification of the issues related to the failed assertion, * the possibility to control better the behavior or the reports of the checks, in particular: * floating point comparison: the tolerance may be provided, either using the `BOOST_TEST` directly with `optional_modifiers`, or with /decorators/ (see [link boost_test.testing_tools.extended_comparison.floating_point here] for more details), * container/collection comparisons: different operations for comparison are provided out of the box for comparing collection of elements (default, per-element, lexicographic), with extended diagnostic on failures (covered in [link boost_test.testing_tools.extended_comparison.collections this] section), * string comparison: C-strings operands are automatically detected and the comparisons are performed as if `std::string` objects were used, * optional failure message, * bitwise comparison, providing extended diagnostic in case of failure [warning To get all the functionalities of `BOOST_TEST` family of assertions, a C++11 capable compiler is required, especially supporting the `auto` and `decltype` keywords and the variadic macros. The documentation focuses on these set of compilers. For compilers not supporting all the features of `BOOST_TEST`, the macro `BOOST_TEST_MACRO_LIMITED_SUPPORT`.] [#boost_test_statement_overloads][h3 Complex statements] `BOOST_TEST` provides an enhanced reporting capability: additional details of the failing operands and operations are provided in the log, as shown on the example below: [bt_example boost_test_macro3..BOOST_TEST enhanced reporting..run-fail] `BOOST_TEST` parses the `statement` and constructs an expression out of it. `statement` may be a complex expressions containing almost any of the overloadable operators in C++: [table [[Class of operation][operators]] [[binary comparisons][`==`, `!=`, `<`, `>`, `<=`, `>=`]] [[arithmetic compositions][`+`, `-`, `*`, `/`, `%`]] [[bitwise compositions][`|`, `&`, `^`, `<<`, `>>`]] [[assignments][`=`, `+=`, `-=`, `*=`, `/=`, `%=`, `<<=`, `>>=`, `&=`, `^=`, `|=`]] ] `statement` is evaluated and cast to `bool`, as if it would appear as argument to an `if` statement: this is the result of the assertion [h3 Uniform reporting] This tool is provided in three variants corresponding to the corresponding [link boost_test.testing_tools.tools_assertion_severity_level severity levels]. These three levels of assertions are reported into the test log and output, as described in details in the section. The granularity of the report depends on the current [link boost_test.utf_reference.rt_param_reference.log_level log level] and [link boost_test.utf_reference.rt_param_reference.report_level report level]. [#boost_test_statement_limitations][h3 Limitations & workaround] There are a few constructions that are however unsupported, but adding an extra bracket usually solves that: * statements containing ternary conditions: those statement should be surrounded by parenthesis as they cannot be overloaded * statements containing commas: those statements will be intercepted by the preprocessor * compound statements containing any logical composition `||`, `&&`. Those are disabled intentionally and should be surrounded by parenthesis BOOST_TEST((true || false)); The full details are given in [link boost_test.testing_tools.internal_details this section]. [bt_example boost_test_macro_workaround..BOOST_TEST limitation and workaround..run] [endsect] [/ boost_test_universal_macro]