大约有 45,000 项符合查询结果（耗时：0.0517秒） [XML]
Should operator
...("w1");
Widget w2("w2");
// These two won't work
{
// Error: operand types are std::ostream << std::ostream
// cout << w1.operator<<(cout) << '\n';
// Error: operand types are std::ostream << Widget
// cout << w1 <&...
What are the differences between type() and isinstance()?
...g)
return treatasscalar(x)
try:
return treatasiter(iter(x))
except TypeError:
return treatasscalar(x)
You could say that basestring is an Abstract Base Class ("ABC")—it offers no concrete functionality to subclasses, but rather exists as a "marker", mainly for use with isinstance. The conc...
What's the point of map in Haskell, when there is fmap?
...ical; when teaching Haskell to beginners the very general type of map made error messages more difficult to understand. In my opinion this wasn't the right way to solve the problem.
Haskell 98 is seen as a step backwards by some Haskellers (including me), previous versions having defined a more ab...
MVC (Laravel) where to add logic
... }
catch (ValidationException $e)
{
// Catch validation errors thrown by service operation.
return Redirect::route('congregations.create')
->withInput(Input::all())
->withErrors($e->getValidator());
}
catch (Exception $e)
{
...
Who architected / designed C++'s IOStreams, and would it still be considered well-designed by today'
...rally considered
outdated.)
I would say NO, for several reasons:
Poor error handling
Error conditions should be reported with exceptions, not with operator void*.
The "zombie object" anti-pattern is what causes bugs like these.
Poor separation between formatting and I/O
This makes stream ob...
How to get the raw value an field?
...ill have invalid input. .valid is defined as the absence of any validation errors (E.g. mismatches, overflows, underflows), of which .badInput is only one kind of error. Note the chart above where .badInput is false, but the input is still invalid.
– Ian Boyd
S...
Is it possible to make a type only movable and not copyable?
... the new struct or enum is itself Copy. If not, the compiler will print an error message. It can also only exist if the type doesn't have a Drop implementation.
To answer the question you didn't ask... "what's up with moves and copy?":
Firstly I'll define two different "copies":
a byte copy, w...
Should unit tests be written for getter and setters?
...is run as part of larger tests. The last pieces to be covered are probably error handling. And if the error handling isn't covered by unit tests it will never be covered. Do you really want to ship a product that contains code that has never ever been run?
– Anders Abel
...
How does deriving work in Haskell?
...n $ (simpleName $ name d, paramsA d, consA d, termsA d)
_ -> error ("derive: not a data type declaration: " ++ show d)
where
consA (DataD _ _ _ cs _) = map conA cs
consA (NewtypeD _ _ _ c _) = [ conA c ]
{- This part no longer works on 7.6.3
p...
Failed to execute 'btoa' on 'Window': The string to be encoded contains characters outside of the La
The error in the title is thrown only in Google Chrome, according to my tests. I'm base64 encoding a big XML file so that it can be downloaded:
...