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Is the pImpl idiom really used in practice?
...about the implementation or just break the encapsulation by using terrible casting tricks. PIMPL solves/mitigates that.
Compilation time
Compilation time is decreased, since only the source (implementation) file of X needs to be rebuilt when you add/remove fields and/or methods to the XImpl class...
Difference between a Structure and a Union
...ome_test_pointer;
some_test_pointer can point to int* or double*. If you cast an address of type test to int*, it will point to its first member, a, actually. The same is true for an union too. Thus, because an union will always have the right alignment, you can use an union to make pointing to so...
What's the meaning of interface{}?
...mment by @NickCraig-Wood. interface{} can point to anything and you need a cast/type assertion to use it.
package main
import (
. "fmt"
"strconv"
)
var c = cat("Fish")
var d = dog("Bone")
func main() {
var i interface{} = c
switch i.(type) {
case cat:
c.Eat() // Fish...
Storing money in a decimal column - what precision and scale?
...onverting a floating point number back to an integer in step 3, don't just cast it - use a math function to round it first. This will usually be round, though in special cases it could be floor or ceil. Know the difference and choose carefully.
Store the type of a number alongside the value
This m...
How to compare two colors for similarity/difference
...t;/b> pctDiffRed = diffRed / 255; is going to give you 0 unless you cast to a float somewhere. <b>2</b> You'll need to multiply by 100 somewhere to get a percentage.
– vaughandroid
Jan 26 '12 at 12:34
...
Why exactly is eval evil?
...nic or other)
pointers
restartable exceptions
self-modifying code
...and a cast of thousands.
If you find yourself having to use any of these powerful, potentially dangerous tools ask yourself three times "why?" in a chain. For example:
"Why do I have to use eval?"
"Because of foo." "Why ...
Checking for empty arrays: count vs empty
...
Alternatively, you can cast the variable as a boolean (implicitly or explicitly):
if( $value )
{
// array is not empty
}
if( (bool) $value )
{
// array is still not empty
}
This method does generate an E_NOTICE if the variable is not define...
returning a Void object
...
If you want to return null as void you need to cast it in some cases: (Void) null
– Patrick Favre
Mar 29 '16 at 10:04
...
How do I check if a list is empty?
... Part 1
The "pythonic" way fails with NumPy arrays because NumPy tries to cast the array to an array of bools, and if x tries to evaluate all of those bools at once for some kind of aggregate truth value. But this doesn't make any sense, so you get a ValueError:
>>> x = numpy.array([0,1]...