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What are copy elision and return value optimization?
....
Copy elision is an optimization implemented by most compilers to prevent extra (potentially expensive) copies in certain situations. It makes returning by value or pass-by-value feasible in practice (restrictions apply).
It's the only form of optimization that elides (ha!) the as-if rule - copy el...
How to avoid null checking in Java?
...dition> is a boolean expression and <object> is an object whose toString() method's output will be included in the error.
An assert statement throws an Error (AssertionError) if the condition is not true. By default, Java ignores assertions. You can enable assertions by passing the optio...
What is the usefulness of `enable_shared_from_this`?
...p == q);
assert(!(p < q || q < p)); // p and q must share ownership
}
The method f() returns a valid shared_ptr, even though it had no member instance. Note that you cannot simply do this:
class Y: public enable_shared_from_this<Y>
{
public:
shared_ptr<Y> f()
{
...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...quires it to work; you tend to find you need the equivalent trick with the stringizing operator too.
Section 6.10.3 of the C99 standard covers 'macro replacement', and 6.10.3.1 covers 'argument substitution'.
After the arguments for the invocation of a function-like macro have been identified,
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Git serve: I would like it that simple
... it down and start it back up too fast.
You can put this into a batch script with an easy to remember name like "gitserve", so you don't need to type it all out again. As suggested in some of the comments, in recent versions of Git you can add an alias to the Git config:
[alias]
serve = !git...
In .NET, which loop runs faster, 'for' or 'foreach'?
...tably faster, why shouldn't you start using it in general? It doesn't take extra time.
– DevinB
Sep 3 '09 at 13:06
50
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Why do pthreads’ condition variable functions require a mutex?
...ad could come out when there was no work to be done. So you had to have an extra variable indicating that work should be done (this was inherently mutex-protected with the condvar/mutex pair here - other threads needed to lock the mutex before changing it however).
It was technically possible for a...
Send Email Intent
...."));
Update: According to marcwjj, it seems that on 4.3, we need to pass string array instead of a string for email address to make it work. We might need to add one more line:
intent.putExtra(Intent.EXTRA_EMAIL, addresses); // String[] addresses
Ref link
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Parse (split) a string in C++ using string delimiter (standard C++)
I am parsing a string in C++ using the following:
17 Answers
17
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Maximum on http header values?
...ders size exceeds that limit.
Related question: How big can a user agent string get?
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