大约有 6,261 项符合查询结果（耗时：0.0188秒） [XML]
When do we have to use copy constructors?
...lass:
class Erroneous
{
public:
Erroneous();
// ... others
private:
Foo* mFoo;
Bar* mBar;
};
Erroneous::Erroneous(): mFoo(new Foo()), mBar(new Bar()) {}
What happens if new Bar throws ? How do you delete the object pointed to by mFoo ? There are solutions (function level try/catch ...), ...
How to pass anonymous types as parameters?
... (when extracting data) is to also pass a selector - i.e. something like:
Foo<TSource, TValue>(IEnumerable<TSource> source,
Func<TSource,string> name) {
foreach(TSource item in source) Console.WriteLine(name(item));
}
...
Foo(query, x=>x.Title);
...
In Perl, how can I read an entire file into a string?
...
local $foo = undef is just the Perl Best Practice (PBP) suggested method. If we are posting snippits of code I'd think doing our best to make it clear would be A Good Thing.
– Danny
Jun 5 '09 a...
What JSON library to use in Scala? [closed]
...:
import com.owlike.genson.defaultGenson_
val json = toJson(Person(Some("foo"), 99))
val person = fromJson[Person]("""{"name": "foo", "age": 99}""")
case class Person(name: Option[String], age: Int)
Disclaimer: I am Gensons author, but that doesn't meen I am not objective :)
...
JavaScript hashmap equivalent
...he following script,
var map = new Map;
map.put('spam', 'eggs').
put('foo', 'bar').
put('foo', 'baz').
put({}, 'an object').
put({}, 'another object').
put(5, 'five').
put(5, 'five again').
put('5', 'another five');
for(var i = 0; i++ < map.size; map.next())
docu...
When to use -retainCount?
...1] would have a retainCount of 1. It doesn't. It's 2.
You'd think that @"Foo" would have a retainCount of 1. It doesn't. It's 1152921504606846975.
You'd think that [NSString stringWithString:@"Foo"] would have a retainCount of 1. It doesn't. Again, it's 1152921504606846975.
Basically, since ...
Using std Namespace
...dant lookup (aka ADL or Koenig lookup):
template< typename T >
void foo( T& x, T& y)
{
using std::swap; // makes std::swap available in this function
// do stuff...
swap( x, y); // will use a T-specific swap() if it exists,
// otherw...
Is it possible only to declare a variable without assigning any value in Python?
...ually going to assign to or use them. I think what you want to do is just
foo = None
which will assign the value None to the variable foo.
EDIT: What you really seem to want to do is just this:
#note how I don't do *anything* with value here
#we can just start using it right inside the loop
fo...
How to test if string exists in file with Bash?
...string matches an entire line, not just a part of it: so if you search for foo, only lines containing exactly foo are matched, not foobar. (There was an error in my examples; it still used some regex syntax. Fixed now.)
– Thomas
Jan 24 '11 at 17:04
...
How to go to each directory and execute a command?
...ommands don't actually care in which directory you execute them. for f in foo bar; do cat "$f"/*.txt; done >output is functionally equivalent to cat foo/*.txt bar/*.txt >output. However, ls is one command that does produce slightly different output depending on how you pass it arguments; sim...