Error C2059: syntax error: ' tag ::*'

Question

  
Hello,
I'm trying to adapt some Microsoft code (member.cpp in Detours) for my case
( I just want to replace :
void CMember::Target(void)
by
QString QString::fromAscii(const char *str, int size):
MS Code :
class CMember
public:
void Target(void);
void CMember::Target(void)
printf(" CMember::Target! (this:%p)\n", this);
//////////////////////////////////////////////////////////////// Detour Class.
class CDetour /* add ": public CMember" to enable access to member variables... */
public:
void Mine_Target(void);
static void (CDetour::* Real_Target)(void);
// Class shouldn't have any member variables or virtual functions.
void CDetour::Mine_Target(void)
printf(" CDetour::Mine_Target! (this:%p)\n", this);
(this->*Real_Target)();
void (CDetour::* CDetour::Real_Target)(void) = (void (CDetour::*)(void))&CMember::Target;
My code :
class CDetour /* add ": public CMember" to enable access to member variables... */
public:
QString Mine_Target(const char *str, int size);
static QString (CDetour::* Real_Target)(const char *str, int size);
// Class shouldn't have any member variables or virtual functions.
QString CDetour::Mine_Target(const char *str, int size)
printf(" CDetour::Mine_Target! (this:%p)\n", this);
(this->*Real_Target)(str, size);
QString (CDetour::* CDetour::Real_Target)(const char *str, int size) = (CDetour::*)(const char *str, int size)&QString::fromAscii;
 But I get :
error C2059: syntax error: '< tag >::*'
for the last line
And If I write instead :
QString (CDetour::* CDetour::Real_Target)(const char *str, int size) = (QString(CDetour::*)(const char *str, int size))&QString::fromAscii;
I get :
error C2440: 'type cast' : impossible to convert from 'QString (__cdecl *)(const char *,int)' into 'QString (__thiscall CDetour::* )(const char *,int)'
Thanks.

Answer 1

On 1/30/2015 11:26 AM, Jeff666 wrote:
Thanks for your answer, but I get the same type cast error :
error C2440: 'type cast ' : impossible to convert from 'QString (__cdecl *)(const char *,int)' into 'CDetour::TargetType'
Ah. QString::fromAscii is a static member - basically, an ordinary function; it doesn't have a "this" pointer. Whereas the original sample you are working from deals with a non-static member function.
I suppose you could so this (though I must admit I don't at all understand the point of the exercise):
class CDetour {
public:
typedef QString (__cdecl *TargetType)(const char *str, int size);
static TargetType Real_Target;
static QString Mine_Target(const char *str, int size) {
return Real_Target(str, size);
CDetour::TargetType CDetour::Real_Target = &QString::fromAscii;
Note that TargetType is no longer a pointer-to-member, but a regular function pointer.
Igor Tandetnik