大约有 16,000 项符合查询结果（耗时：0.0322秒） [XML]
Dynamically generating a QR code with PHP [closed]
I'm trying to generate QR codes on my website. All they have to do is have a URL in them, which a variable on my site will provide. What would be the easiest way to do this?
...
Python list subtraction operation
...it__(self, *args):
super(MyList, self).__init__(args)
def __sub__(self, other):
return self.__class__(*[item for item in self if item not in other])
you can then use it like:
x = MyList(1, 2, 3, 4)
y = MyList(2, 5, 2)
z = x - y
But if you don't absolutely need list prop...
Can a class member function template be virtual?
I have heard that C++ class member function templates can't be virtual. Is this true?
12 Answers
...
How to perform better document version control on Excel files and SQL schema files
...n charge of several Excel files and SQL schema files. How should I perform better document version control on these files?
...
How do I return multiple values from a function? [closed]
...tuples were added in 2.6 for this purpose. Also see os.stat for a similar builtin example.
>>> import collections
>>> Point = collections.namedtuple('Point', ['x', 'y'])
>>> p = Point(1, y=2)
>>> p.x, p.y
1 2
>>> p[0], p[1]
1 2
In recent versions of P...
Google Analytics - Failed to load resource: http://www.google-analytics.com/ga.js
I've been noticing this error on Chrome's console for a while now:
8 Answers
8
...
Embed SVG in SVG?
...ave the following as recursion.svg:
<svg width="100%" height="100%" viewBox="-100 -100 200 200" version="1.1"
xmlns="http://www.w3.org/2000/svg">
<circle cx="-50" cy="-50" r="30" style="fill:red" />
<image x="10" y="20" width="80" height="80" href="recursion.svg" />
</s...
When to use std::forward to forward arguments?
...s && ...args)
{
g(std::forward<Args>(args)...);
}
That's because of the reference collapsing rules: If T = U&, then T&& = U&, but if T = U&&, then T&& = U&&, so you always end up with the correct type inside the function body. Finally, you ne...
Is there more to an interface than having the correct methods
...
Interfaces are a way to make your code more flexible. What you do is this:
Ibox myBox=new Rectangle();
Then, later, if you decide you want to use a different kind of box (maybe there's another library, with a better kind of box), you switch your code to:
Ibox myBox=new ...
How do I base64 encode (decode) in C?
I have binary data in an unsigned char variable.
I need to convert them to PEM base64 in c.
I looked in openssl library but i could not find any function.
Does any body have any idea?
...