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How much is the overhead of smart pointers compared to normal pointers in C++?
...#include <iostream>
#include <chrono>
#include <thread>
uint32_t n = 100000000;
void t_m(void){
auto a = (char*) malloc(n*sizeof(char));
for(uint32_t i=0; i<n; i++) a[i] = 'A';
}
void t_u(void){
auto a = std::unique_ptr<char[]>(new char[n]);
for(uint32_t ...
What does static_assert do, and what would you use it for?
...ly occupy 32 bits of memory, leaving 16 of them unused (and thus the macro UINT_MAX would be equal to 65535). So the way you describe the first static assertion ("unsigned int object having exactly 32 bits") is misleading. To match your description, this assertion should be included as well : static...
Convert interface{} to int
...== %T\n", t, t)
i = int(t) // standardizes across systems
case uint8:
fmt.Printf("%d == %T\n", t, t)
i = int(t) // standardizes across systems
case uint16:
fmt.Printf("%d == %T\n", t, t)
i = int(t) // standardizes across systems
case uint32:
...
Timer function to provide time in nano seconds using C++
...rors, and may yield incorrect timing values on certain processors)
inline uint64_t rdtsc()
{
uint32_t lo, hi;
__asm__ __volatile__ (
"xorl %%eax, %%eax\n"
"cpuid\n"
"rdtsc\n"
: "=a" (lo), "=d" (hi)
:
: "%ebx", "%ecx" );
return (uint64_t)hi << 32...
Why unsigned integer is not available in PostgreSQL?
...additional constraint.
For an concrete example you could use
CREATE DOMAIN uint2 AS int4
CHECK(VALUE >= 0 AND VALUE < 65536);
Here is what psql gives when I try to abuse the type.
DS1=# select (346346 :: uint2);
ERROR: value for domain uint2 violates check constraint "uint2_check"
...
How to enumerate an enum with String type?
...orOfOne(unsafeBitCast((), T.self)))
case 1: cast = { unsafeBitCast(UInt8(truncatingBitPattern: $0), T.self) }
case 2: cast = { unsafeBitCast(UInt16(truncatingBitPattern: $0), T.self) }
case 4: cast = { unsafeBitCast(UInt32(truncatingBitPattern: $0), T.self) }
case 8: ...
How to get current timestamp in milliseconds since 1970 just the way Java gets
...ast<milliseconds>(d)
translate std::chrono::milliseconds to integer (uint64_t to avoid overflow)
#include <chrono>
#include <cstdint>
#include <iostream>
uint64_t timeSinceEpochMillisec() {
using namespace std::chrono;
return duration_cast<milliseconds>(system_cl...
How to have stored properties in Swift, the same way I had on Objective-C?
...roperties:
for Swift 1
import ObjectiveC
private var xoAssociationKey: UInt8 = 0
extension UIView {
var xo: PFObject! {
get {
return objc_getAssociatedObject(self, &xoAssociationKey) as? PFObject
}
set(newValue) {
objc_setAssociatedObject(...
How to count the number of set bits in a 32-bit integer?
...e, you may need to adjust it to work for a particular language (e.g. using uint32_t for C++ and >>> in Java):
int numberOfSetBits(uint32_t i)
{
// Java: use int, and use >>> instead of >>
// C or C++: use uint32_t
i = i - ((i >> 1) & 0x55555555);
...
How can I declare and define multiple variables in one line using C++?
...r if they just happen to be the same type now but don't really need to be (uint8_t height, width; might turn into uint8_t height; uint16_t width; in the future and should have been uint8_t height; uint8_t width; to begin with).
– altendky
Jun 17 '15 at 15:08
...