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first object's destructor is called if the tt([]) is omitted.
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Conversely, if tt(delete[]) is called in a situation where tt(delete)
36
should have been called the results are unpredictable, and will most likely
37
cause the program to crash. This problematic behavior is caused by the way the
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run-time system stores information about the size of the allocated array
39
(usually right em(before) the array's first element). If a single object is
40
allocated the array-specific information is not available, but it is
41
nevertheless assumed present by tt(delete[]). This latter operator will
42
interpret bogus values before the array's first element as size information,
43
thus usually causing the program to fail.
36
should have been called the results are unpredictable, and the program will
37
most likely crash. This problematic behavior is caused by the way the run-time
38
system stores information about the size of the allocated array (usually right
39
em(before) the array's first element). If a single object is allocated the
40
array-specific information is not available, but it is nevertheless assumed
41
present by tt(delete[]). Thus this latter operator encounters bogus values in
42
the memory locations just before the array's first element. It then dutifully
43
inteerprets the value it encounters there as size information, usually causing
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If no destructor is defined, a emi(trivial destructor) is defined by the
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compiler. The trivial destructor ensures that the destructors of composed
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objects (as well as the destructors of em(base classes) if a class is a
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derived class, cf. chapter ref(INHERITANCE)) are called. This has serious
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implications: objects allocating memory will cause a i(memory leak) unless
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precautionary measures are taken (by defining an appropriate
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implications: objects allocating memory create memory leaks hi(memory leak)
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unless precautionary measures are taken (by defining an appropriate
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destructor). Consider the following program:
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verbinclude(examples/stringstorenodelete.cc)
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This program produces no output at all. Why is this? The variable tt(ptr)
added
removed
yo/memory/objectp.yo
