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How do I forward declare an inner class? [duplicate]
...want, but here is a workaround, if you are willing to use templates:
// Foo.h
struct Foo
{
export template<class T> void Read(T it);
};
// Foo.cpp
#include "Foo.h"
#include "Container.h"
/*
struct Container
{
struct Inner { };
};
*/
export template<>
void Foo::Read<...
Rails - link_to helper with data-* attribute [duplicate]
... in... Rails has a default :data hash
= link_to body, url, :data => { :foo => 'bar', :this => 'that' }
One gotcha - you must surround symbols with quotes if they include a dash:
:data => { :'foo-bar' => 'that' }
Update: In Rails 4, underscores are automatically converted to dash...
What does it mean in shell when we put a command inside dollar sign and parentheses: $(command)
... of the $ like ${HOME} gives the value of HOME. Usage of the $ like $(echo foo) means run whatever is inside the parentheses in a subshell and return that as the value. In my example, you would get foo since echo will write foo to standard out
...
Using Git, show all commits that are in one branch, but not the other(s)
...ich I would like to delete. However, before doing so, I want to check that all commits made to this branch were at some point merged into some other branch. Thus, I'd like to see all commits made to my current branch which have not been applied to any other branch [or, if this is not possible withou...
Does JavaScript have “Short-circuit” evaluation?
... in times of JIT-compiling-magic in javascript implementations, one does really want to know if something is "the standard" , or potentially subject to the implementation. The way a condition statement with Binary Logical Operators is evaluated and (short-curcuit) is a standard behavior ecma-interna...
How do I Moq a method that has an optional argument in its signature without explicitly specifying i
...ice right now is to explicitly include the bool parameter in the setup for Foo.
I don't think it defeats the purpose of specifying a default value. The default value is a convenience for calling code, but I think that you should be explicit in your tests. Say you could leave out specifying the bool...
Is it necessary to explicitly remove event handlers in C#
...ng:
using System;
public class Publisher
{
public event EventHandler Foo;
public void RaiseFoo()
{
Console.WriteLine("Raising Foo");
EventHandler handler = Foo;
if (handler != null)
{
handler(this, EventArgs.Empty);
}
else
...
What is the difference between instanceof and Class.isAssignableFrom(…)?
...s Y which extends Z which extends A), results might be different.
it is usually advised to write the code first picking one of the operators (the most convenient) and then profile your code to check if there are a performance bottleneck. Maybe this operator is negligible in the context of your code,...
e.printStackTrace equivalent in python
... = logging.getLogger()
logger.setLevel(logging.DEBUG)
def f():
a = { 'foo': None }
# the following line will raise KeyError
b = a['bar']
def g():
f()
try:
g()
except Exception as e:
logger.error(str(e), exc_info=True)
And it will output:
'bar'
Traceback (most recent cal...
What's wrong with nullable columns in composite primary keys?
...
Primary keys are for uniquely identifying rows. This is done by comparing all parts of a key to the input.
Per definition, NULL cannot be part of a successful comparison. Even a comparison to itself (NULL = NULL) will fail. This means a key containing NULL would not work.
Additonally, NULL is al...