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Which is better for string literals, standard string or character array?
I mean to say for constant strings, say
const char name[] = "so"; //or to use const string name = "so";
Started by Programmer on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
Because passing string literals into functions....
I tend to favour const std::string over const char * for string literals.
std::string rather than const char* , as in the latter case size is lost, and will possibly need.
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I keep receiving a C2664 conversion error in visual studio
It tells me that it can't convert parameter 1 from const std::string to std::string&. I tried adding/removing the const in the stringToWstring prototype and in the function itself and the error...
Started by styx777 on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
Separator<wchar_t>, std::wstring::const_iterator, std::wstring>
In general when debugging std::_String_const_iterator<_Elem,_Traits,_Alloc> in the error message from the second const std....
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How can I convert an std::string to a char* or a const char*?
Answer Snippets (Read the full thread at stackoverflow):
You can use &mystring[0] to get a char * pointer of the string or you'll get a buffer... .
String to a function that needs const char* you can use
std::string str; const char * c = str.c_strUse the .c_str() method for const char *.
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Is there an elegant way to create and initialize a const std::vector<const T> like const T a[] = { ... } to a fixed (and small) number of values?
I need to call a function frequently which expects a vector<T> , but these values will never ...
Answer Snippets (Read the full thread at stackoverflow):
}; const std::vector<const T> s_blah....
const int* myInt = std::find( &MyInts[0], &MyInts it in two steps:
namespace { const T s_actual_array[] = { ...
Would use algorithms against a const vector...
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Sqlite3_column_text returns a const unsigned char*, how do I convert this to a std::string? I've tried std::string(), but I get an error.
Code:
temp_doc.uuid = std::string(sqlite3_column_text(this->stmts.read_documents, 0));
Error:
1>.\storage_manager...
Started by LM on
, 8 posts
by 8 people.
Answer Snippets (Read the full thread at stackoverflow):
You could try:
temp_doc.uuid = std::string(reinterpret_cast<const char*>( sqlite3_column_text(this->stmts.read_documents, 0) ));
While std::string could have a constructor that takes const it to const char* ....
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Let's say that I've got a :
#include <utility> using namespace std; typedef pair<int, int> my_pair;
how do I initialize a const my_pair ?
Started by Maciek on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Use its constructor:
const my_pair p( 1, 2 );
const my_pair p = my_pair(3, 2);
const my_pair p = std::make_pair( 2, 3);.
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Is there a reason why passing a reference to a STL map as const causes the [] operator to break? I get this compiler error (gcc 4.2) when I use const:
error: no match for ‘operator[]’ in ‘map[name]’
Here's the function prototype:
void func(const char ...
Started by Joe on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
Operator[] will add the element_iterator instead of iterator :
std::map<std::string, std::string>::const_iterator it; it = map.find....
}
Probably because there is no const operator[] in std::map.
() ) { //...
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Hi
I have a function which takes const std::wstring& font_family, i.e.
Font Font::CreateFont(const std::wstring& font_family){ ... }
By question is how can I call that funcion by passing a string literal (e.g monospace)?
I tried
CreateFont("monospace"...
Started by n179911 on
, 3 posts
by 3 people.
Answer Snippets (Read the full thread at stackoverflow):
std::wstring s(L"Monospace"); CreateFont(s);
the ctor for wstring doesn't accept narrow.
String.
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I have a class which returns a typed pointer to a "const TCHAR". I need to convert it to a std::string but I have not found a way to make this happen.
Can anyone provide some insight on how to convert it?
Started by TERACytE on
, 5 posts
by 5 people.
Answer Snippets (Read the full thread at stackoverflow):
Either....
You can the encoding.
Containing the character like this:
const TCHAR example = _T('Q'); std::string mystring(1, example macros for this, e.g.:
std::wstring str = CT2W(_T("A TCHAR string"));
CT2W = Const Text To Wide.
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I'm having trouble with some valarray function pointer code:
double (*fp)(double) = sin; valarray<double> (*fp)(const valarray<double> &) = sin;
The first compiles, the second gives:
error: no matches converting function 'sin' to type 'class...
Started by robert on
, 4 posts
by 4 people.
Answer Snippets (Read the full thread at stackoverflow):
Note, that you should qualify all uses of sin says about sin(valarray<T>... .
Valarray<double> (*fp)(const valarray<double> &) = std::sin;
That should work.
You speak about std::sin in the title, but then assign ::sin .
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