QtCreator .pro 文件中的 *= 是什么意思？
What means *= in QtCreator .pro files?
勾选this pro file。它有这样的行：
QMAKE_CXXFLAGS *= /openmp
我很容易理解 += 添加选项或 -= 删除选项...但是 *= 在这里意味着什么？
根据 Qt 文档中的 Operators 部分：
The *= operator adds a value to the list of values in a variable, but
only if it is not already present. This prevents values from being
included many times in a variable. For example:
DEFINES *= USE_MY_STUFF
In the above line, USE_MY_STUFF will only be
added to the list of pre-processor defines if it is not already
defined. Note that the unique() function can also be used to ensure
that a variable only contains one instance of each value.
勾选this pro file。它有这样的行：
QMAKE_CXXFLAGS *= /openmp
我很容易理解 += 添加选项或 -= 删除选项...但是 *= 在这里意味着什么？
根据 Qt 文档中的 Operators 部分：
The
*=operator adds a value to the list of values in a variable, but only if it is not already present. This prevents values from being included many times in a variable. For example:DEFINES *= USE_MY_STUFFIn the above line,
USE_MY_STUFFwill only be added to the list of pre-processor defines if it is not already defined. Note that theunique()function can also be used to ensure that a variable only contains one instance of each value.