dot-operator

Does “T const&t = C().a;” lengthen the lifetime of “a”?

由 Deadly 提交于 2020-01-01 23:55:33
问题 The following scenario is given, to be interpreted as C++0x code: struct B { }; struct A { B b; }; int main() { B const& b = A().b; /* is the object still alive here? */ } Clang and GCC (trunk version as of 2011/02) behave differently: Clang lengthens the lifetime. GCC moves B to a new temporary object, and then binds the reference to that new temporary. I cannot find either behavior can be derived from the words of the Standard. The expression A().b is not a temporary (see 5.2.5). Can anyone

Does “T const&t = C().a;” lengthen the lifetime of “a”?

由 老子叫甜甜 提交于 2020-01-01 23:55:27
问题 The following scenario is given, to be interpreted as C++0x code: struct B { }; struct A { B b; }; int main() { B const& b = A().b; /* is the object still alive here? */ } Clang and GCC (trunk version as of 2011/02) behave differently: Clang lengthens the lifetime. GCC moves B to a new temporary object, and then binds the reference to that new temporary. I cannot find either behavior can be derived from the words of the Standard. The expression A().b is not a temporary (see 5.2.5). Can anyone

Dot operator in haskell with multi-parameter functions

由 烂漫一生 提交于 2019-12-18 13:27:15
问题 I want to write a function point-free in haskell, to keep things simple lets say I want to make this function: maxmin :: Ord a => a -> a -> a -> a maxmin a b c = max a (min b c) I can improve this to maxmin a b = (max a) . (min b) but is there any way to get rid of a and b? 回答1: I wouldn't say this is simplier but here you go: maxmin :: Ord a => a -> a -> a -> a maxmin = (. min) . (.) . max (Generated with pl tool from lambdabot http://www.haskell.org/haskellwiki/Pointfree) lambdabot> pl

JavaScript Functional Programming - Chaining Functions and using an anonymous function

由 ∥☆過路亽．° 提交于 2019-12-10 12:06:28
问题 I was doing a question on CodeWars and practicing some functional programming when I encountered a problem while trying to apply a function to a value. So I made a pass() function that accepts a function as an argument so that I could use an anonymous function to manipulate that value and then return it. So, in this case, it takes the value from reduce and passes it to a function so it can manipulate that value then return it. It WORKS but I really don't want to add a method to the Object

Does “T const&t = C().a;” lengthen the lifetime of “a”?

由 风流意气都作罢 提交于 2019-12-04 22:30:13
The following scenario is given, to be interpreted as C++0x code: struct B { }; struct A { B b; }; int main() { B const& b = A().b; /* is the object still alive here? */ } Clang and GCC (trunk version as of 2011/02) behave differently: Clang lengthens the lifetime. GCC moves B to a new temporary object, and then binds the reference to that new temporary. I cannot find either behavior can be derived from the words of the Standard. The expression A().b is not a temporary (see 5.2.5). Can anyone please explain the following to me? Desired behavior (the intent of the committee) The behavior as you

Dot (“.”) operator and arrow (“->”) operator use in C vs. Objective-C

由 偶尔善良 提交于 2019-11-26 10:09:36
I'm trying to wrap my head around some of the differences in usage and syntax in C vs. Objective-C. In particular, I want to know how (and why) the usage differs for the dot operator and the arrow operator in C vs. Objective-C. Here is a simple example. C Code: // declare a pointer to a Fraction struct Fraction *frac; ... // reference an 'instance' variable int n = (*frac).numerator; // these two expressions int n = frac->numerator; // are equivalent Objective-C Code: // declare a pointer to a Fraction Fraction *frac = [[Fraction alloc] init]; ... // reference an instance variable int n = frac

Dot (“.”) operator and arrow (“->”) operator use in C vs. Objective-C

由 烂漫一生 提交于 2019-11-26 03:27:34
问题 I\'m trying to wrap my head around some of the differences in usage and syntax in C vs. Objective-C. In particular, I want to know how (and why) the usage differs for the dot operator and the arrow operator in C vs. Objective-C. Here is a simple example. C Code: // declare a pointer to a Fraction struct Fraction *frac; ... // reference an \'instance\' variable int n = (*frac).numerator; // these two expressions int n = frac->numerator; // are equivalent Objective-C Code: // declare a pointer
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