大约有 10,000 项符合查询结果（耗时：0.0332秒） [XML]
What does map(&:name) mean in Ruby?
...
It's shorthand for tags.map(&:name.to_proc).join(' ')
If foo is an object with a to_proc method, then you can pass it to a method as &foo, which will call foo.to_proc and use that as the method's block.
The Symbol#to_proc method was originally added by ActiveSupport but has be...
How to version control a record in a database
...
Let's say you have a FOO table that admins and users can update. Most of the time you can write queries against the FOO table. Happy days.
Then, I would create a FOO_HISTORY table. This has all the columns of the FOO table. The primary key i...
Template default arguments
...
You have to do:
Foo<> me;
The template arguments must be present but you can leave them empty.
Think of it like a function foo with a single default argument. The expression foo won't call it, but foo() will. The argument syntax mus...
C++ static virtual members?
...ring getTypeInformation() { return getTypeInformationStatic(); }
};
class Foo: public Object
{
public:
static string getTypeInformationStatic() { return "derived class";}
virtual string getTypeInformation() { return getTypeInformationStatic(); }
};
What if base class has a great number of...
Abort makefile if variable not set
...fined, ...) from inside the recipe
Just move the check into the recipe:
foo :
@:$(call check_defined, BAR, baz value)
The leading @ sign turns off command echoing and : is the actual command, a shell no-op stub.
Showing target name
The check_defined function can be improved to also outp...
Adding information to an exception?
...
I'd do it like this so changing its type in foo() won't require also changing it in bar().
def foo():
try:
raise IOError('Stuff')
except:
raise
def bar(arg1):
try:
foo()
except Exception as e:
raise type(e)(e.message + ...
How to build & install GLFW 3 and use it in a Linux project
Last night I was working late trying to build the GLFW 3 packages for Linux from source. This process took me a very long time, about 3 hours in total, partly because I am unfamiliar with CMake, and partly because I am was unfamiliar with GLFW.
...
fs: how do I locate a parent folder?
...
Try this:
fs.readFile(__dirname + '/../../foo.bar');
Note the forward slash at the beginning of the relative path.
share
|
improve this answer
|
...
Java 8: How do I work with exception throwing methods in streams?
...meException.
A normal wrapping idiom is something like:
private void safeFoo(final A a) {
try {
a.foo();
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
(Supertype exception Exception is only used as example, never try to catch it yourself)
Then you can ...