<ol>
<li><a href="#hl_assert">Assert Liberally</a>
<li><a href="#hl_preincrement">Prefer Preincrement</a>
+ <li><a href="#hl_avoidendl">Avoid endl</a>
<li><a href="#hl_exploitcpp">Exploit C++ to its Fullest</a>
</ol>
<li><a href="#iterators">Writing Iterators</a>
<pre>
inline Value *getOperand(unsigned i) {
- assert(i < Operands.size() && "getOperand() out of range!");
+ assert(i < Operands.size() && "getOperand() out of range!");
return Operands[i];
}
</pre>
Here are some examples:
<pre>
- assert(Ty->isPointerType() && "Can't allocate a non pointer type!");
+ assert(Ty->isPointerType() && "Can't allocate a non pointer type!");
assert((Opcode == Shl || Opcode == Shr) && "ShiftInst Opcode invalid!");
- assert(idx < getNumSuccessors() && "Successor # out of range!");
+ assert(idx < getNumSuccessors() && "Successor # out of range!");
assert(V1.getType() == V2.getType() && "Constant types must be identical!");
- assert(Succ->front()->isPHINode() && "Only works on PHId BBs!");
+ assert(isa<PHINode>(Succ->front()) && "Only works on PHId BBs!");
</pre><p>
You get the idea...<p>
The semantics of postincrement include making a copy of the value being incremented, returning it, and then preincrementing the "work value". For primitive types, this isn't a big deal... but for iterators, it can be a huge issue (for example, some iterators contains stack and set objects in them... copying an iterator could invoke the copy ctor's of these as well). In general, get in the habit of always using preincrement, and you won't have a problem.<p>
+<!-- _______________________________________________________________________ -->
+</ul><a name="hl_avoidendl"><h4><hr size=0>Avoid endl</h4><ul>
+
+The <tt>endl</tt> modifier, when used with iostreams outputs a newline to the output stream specified. In addition to doing this, however, it also flushes the output stream. In other words, these are equivalent:<p>
+
+<pre>
+ cout << endl;
+ cout << "\n" << flush;
+</pre>
+
+Most of the time, you probably have no reason to flush the output stream, so it's better to use a literal <tt>"\n"</tt>.<p>
+
+
<!-- _______________________________________________________________________ -->
</ul><a name="hl_exploitcpp"><h4><hr size=0>Exploit C++ to its Fullest</h4><ul>
<address><a href="mailto:sabre@nondot.org">Chris Lattner</a></address>
<!-- Created: Tue Jan 23 15:19:28 CST 2001 -->
<!-- hhmts start -->
-Last modified: Mon Oct 1 08:17:21 CDT 2001
+Last modified: Sun Jan 20 13:01:02 CST 2002
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