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“Undefined reference to” template class constructor [duplicate]
...e in order to ensure this problem never happens! (cola<int>, cola<char>, cola<ostream>, cola< cola<int> > ... and so on ...)
The two answers are:
Tell the compiler, at the end of cola.cpp, which particular template classes will be required, forcing it to compile cola...
Are JavaScript strings immutable? Do I need a “string builder” in JavaScript?
...
They are immutable. You cannot change a character within a string with something like var myString = "abbdef"; myString[2] = 'c'. The string manipulation methods such as trim, slice return new strings.
In the same way, if you have two references to the same string...
Yes/No message box using QMessageBox
...lude <QApplication>
#include <QMessageBox>
int main(int argc, char **argv)
{
QApplication app{argc, argv};
while (QMessageBox::question(nullptr,
qApp->translate("my_app", "Test"),
qApp->translate("my_app", "...
Get an OutputStream into a String
...tring constructor, the codepage can be a String or an instance of java.nio.charset.Charset. A possible value is java.nio.charset.StandardCharsets.UTF_8.
The method toString() accepts only a String as a codepage parameter (stand Java 8).
...
C++ STL Vectors: Get iterator from index?
... legal to do this folowing, according to me:
int main()
{
void foo(const char *);
sdt::vector<char> vec;
vec.push_back('h');
vec.push_back('e');
vec.push_back('l');
vec.push_back('l');
vec.push_back('o');
vec.push_back('/0');
foo(&vec[0]);
}
Of course, either foo must not copy the ad...
Replacing a 32-bit loop counter with 64-bit introduces crazy performance deviations with _mm_popcnt_
...;
#include <chrono>
#include <x86intrin.h>
int main(int argc, char* argv[]) {
using namespace std;
uint64_t size=1<<20;
uint64_t* buffer = new uint64_t[size/8];
char* charbuffer=reinterpret_cast<char*>(buffer);
for (unsigned i=0;i<size;++i) charbuffer[i]=...
Difference between decimal, float and double in .NET?
... | | | with 28 or 29 significant figures |
| char | System.Char | N/A | 2 | Any Unicode character (16 bit) |
| bool | System.Boolean | N/A | 1 / 2 | true or false |
+---------+----------------+-------...
How to exclude this / current / dot folder from find “type d”
...his particular case (.), golfs better than the mindepth solution (24 vs 26 chars), although this is probably slightly harder to type because of the !.
To exclude other directories, this will golf less well and requires a variable for DRYness:
D="long_name"
find "$D" ! -path "$D" -type d
My decis...
Efficient string concatenation in C++
...tor+ is not efficient:
Take a look at this interface:
template <class charT, class traits, class Alloc>
basic_string<charT, traits, Alloc>
operator+(const basic_string<charT, traits, Alloc>& s1,
const basic_string<charT, traits, Alloc>& s2)
You can see t...
What is the difference between an int and an Integer in Java and C#?
...nt is not an object.
int is one of the few primitives in Java (along with char and some others). I'm not 100% sure, but I'm thinking that the Integer object more or less just has an int property and a whole bunch of methods to interact with that property (like the toString() method for example). So...
