Questions tagged [scope-resolution]
72 questions
512
votes
9 answers
What is the meaning of prepended double colon "::"?
I found this line of a code in a class which I have to modify:
::Configuration * tmpCo = m_configurationDB;//pointer to current db
and I don't know what exactly means the double colon prepended to the class name. Without that I would read:…
rmbianchi
- 6,241
- 6
- 26
- 27
94
votes
2 answers
vim does not find and replace simple phrase that is clearly present
I have a simple vim problem that Google hasn't managed to help me with. Any thoughts are appreciated.
I do the following search and replace:
:s/numnodes/numnodes1/g
On a file containing the following text:
numprocs=0
numnodes=0
I get
E486:…
Mark C.
- 1,773
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- 26
66
votes
2 answers
What does C++ syntax “A::B:A {};” mean
What does C++ syntax struct A::B:A {}; mean? Where is this name definition (or access) described in the C++ standard?
#include
struct B;
struct A {
struct B;
};
struct A::B:A {
};
int main() {
A::B::A::B b;
…
devsh
- 549
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- 4
- 7
42
votes
7 answers
Why does C++ need the scope resolution operator?
(I know what the scope resolution operator does, and how and when to use it.)
Why does C++ have the :: operator, instead of using the . operator for this purpose? Java doesn't have a separate operator, and works fine. Is there some difference…
Karu
- 4,512
- 4
- 30
- 31
16
votes
2 answers
In C++, what is the scope resolution ("order of precedence") for shadowed variable names?
In C++, what is the scope resolution ("order of precedence") for shadowed variable names? I can't seem to find a concise answer online.
For example:
#include
int shadowed = 1;
struct Foo
{
Foo() : shadowed(2) {}
void bar(int…
Emile Cormier
- 28,391
- 15
- 94
- 122
15
votes
3 answers
whats the difference between dot operator and scope resolution operator
I just wanted to know the difference between . operator and :: operator?
defiant
- 3,161
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14
votes
1 answer
C++0x decltype and the scope resolution operator
With a class such as Foo:
struct Foo { static const int i = 9; };
I find that GCC 4.5 will reject the following
Foo f;
int x = decltype(f)::i;
It will work if I use an intermediate typedef, such as:
typedef decltype(f) ftype;
int x =…
user2023370
- 10,488
- 6
- 50
- 83
14
votes
4 answers
What does the "::" mean in "::tolower"?
I've seen code like this:
std::string str = "wHatEver";
std::transform(str.begin(), str.end(), str.begin(), ::tolower);
And I have a question: what does mean :: before tolower?
and std::tolower not works, but ::tolower works OK
VextoR
- 5,087
- 22
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- 109
11
votes
4 answers
Difference between this->field and Class::field?
I'm wondering something in C++.
Admitting the following code:
int bar;
class Foo
{
public:
Foo();
private:
int bar;
};
Inside my class, is there any difference between this->bar and Foo::bar? Are there cases where one is invalid?
Bryan Peeters
- 161
- 10
11
votes
2 answers
What does ::new mean?
When examining the MS directX 11 DXUT example, the following code appeared:
template HRESULT CGrowableArray ::SetSize( int nNewMaxSize )
{
int nOldSize = m_nSize;
if( nOldSize > nNewMaxSize )
{
assert( m_pData );
if(…
Lycoress
- 113
- 1
- 7
10
votes
2 answers
Using fully qualified name for std namespace in C++
If name in C++ is not fully qualified, e.g. std::cout, it can lead to an unintentional error, such as mentioned at https://en.cppreference.com/w/cpp/language/qualified_lookup. But using a fully qualified name for ::std namespace, e.q. ::std::cout,…
Kam
- 211
- 1
- 8
9
votes
2 answers
template method and default template argument
My problem can be resumed by the following piece of code:
template struct C2;
template
struct C1
{
template class Container = C2>
void m() {}
};
template …
lrleon
- 2,610
- 3
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- 38
9
votes
1 answer
C++ global namespace access from within another namespace
In the C++ code below, foobar is defined first for a single double parameter, and then again for a single parameter of type Foo. Both are defined within the global namespace.
Within the one namespace, a further overload of foobar is defined, with a…
user2023370
- 10,488
- 6
- 50
- 83
8
votes
1 answer
:: scope resolution operator in front of a template function call in c++
I'm stuck with templates and scope resolution operator. I found these line in a file, I'm not able to figure out why we are using :: in front of a template function call, as of my knowledge we can only use :: in front of variables when refering to a…
Vikram Singh
- 273
- 1
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- 10
8
votes
7 answers
What is the purpose of "::delete" in C++?
I'm currently looking at C++ code that uses ::delete to delete a pointer.
A meaningless example of this is:
void DoWork(ExampleClass* ptr)
{
::delete ptr;
}
What is the purpose of using the delete keyword in this way?
Bryan Muscedere
- 572
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