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From: ycy@walt.cc.utexas.edu (Joseph Yip)
Newsgroups: comp.lang.c++
Subject: How to do A = B + C + D
Message-ID: <20277@ut-emx.UUCP>
Date: 30 Oct 89 20:26:48 GMT
Sender: news@ut-emx.UUCP
Reply-To: ycy@walt.cc.utexas.edu (Joseph Yip)
Distribution: usa
Organization: The University of Texas at Austin, Austin, Texas
Lines: 25


Last week, our lecture was on operator overloading. However, we were
not able to code class assignment and addition like A = B + C + D without
losing chunk of memory.

	String A, B, C, D;

	...

	String& String::operator+(String& S) {
		String *tmp = new String;
		...
	}

By using temporary variable, the addition operation can be performed without
altering B, C, and D. Since the member function operator+() will be called
twice in A=B+C+D expression, two temporary variables will be created. The
problem is how to dispose the temporary variable which is created during
the first call to operator+() after B+C+D has finished. 
	A = B + C does not have this problem because after B + C operation, the 
new temporary variable will be assigned to A.

Any better ideas? Thank you.

Joseph Yip