general: retrieval of bool result from argument

...bstraction/src/abstraction/AnyaryOperationAbstraction.cpp

alib2abstraction/src/abstraction/RawAbstraction.cpp

alib2cli/src/environment/Environment.cpp

alib2cli/src/readline/IstreamLineInterface.h

alib2data/src/common/SparseBoolVector.hpp

alib2data/test-src/common/SparseBoolVectorTest.cpp

alib2std/src/extensions/memory.hpp

alib2std/test-src/extensions/IstreamTest.cpp

alib2std/test-src/extensions/container/VectorTest.cpp

alib2str/src/common/lexer.cpp