X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/17e22c50bfd623e2b3b393dbcb838e82c76f2e69..38534f596974042130716a26276e9564b0b72295:/include/wx/scopeguard.h diff --git a/include/wx/scopeguard.h b/include/wx/scopeguard.h index 8d5795f13f..434c89768d 100644 --- a/include/wx/scopeguard.h +++ b/include/wx/scopeguard.h @@ -11,8 +11,9 @@ /* Acknowledgements: this header is heavily based on (well, almost the exact - copy of) wxScopeGuard.h by Andrei Alexandrescu and Petru Marginean published + copy of) ScopeGuard.h by Andrei Alexandrescu and Petru Marginean published in December 2000 issue of C/C++ Users Journal. + http://www.cuj.com/documents/cujcexp1812alexandr/ */ #ifndef _WX_SCOPEGUARD_H_ @@ -26,6 +27,30 @@ // helpers // ---------------------------------------------------------------------------- +#ifdef __WATCOMC__ + +// WATCOM-FIXME: C++ of Open Watcom 1.3 doesn't like OnScopeExit() created +// through template so it must be workarounded with dedicated inlined macro. +// For compatibility with Watcom compilers wxPrivate::OnScopeExit must be +// replaced with wxPrivateOnScopeExit but in user code (for everyone who +// doesn't care about OW compatibility) wxPrivate::OnScopeExit still works. + +#define wxPrivateOnScopeExit(guard) \ + { \ + if ( !(guard).WasDismissed() ) \ + { \ + wxTRY \ + { \ + (guard).Execute(); \ + } \ + wxCATCH_ALL(;) \ + } \ + } + +#define wxPrivateUse(n) wxUnusedVar(n) + +#else + namespace wxPrivate { // in the original implementation this was a member template function of @@ -52,6 +77,11 @@ namespace wxPrivate } } // namespace wxPrivate +#define wxPrivateOnScopeExit(n) wxPrivate::OnScopeExit(n) +#define wxPrivateUse(n) wxPrivate::Use(n) + +#endif + // ============================================================================ // wxScopeGuard for functions and functors // ============================================================================ @@ -65,6 +95,12 @@ class wxScopeGuardImplBase public: wxScopeGuardImplBase() : m_wasDismissed(false) { } + wxScopeGuardImplBase(const wxScopeGuardImplBase& other) + : m_wasDismissed(other.m_wasDismissed) + { + other.Dismiss(); + } + void Dismiss() const { m_wasDismissed = true; } // for OnScopeExit() only (we can't make it friend, unfortunately)! @@ -73,12 +109,6 @@ public: protected: ~wxScopeGuardImplBase() { } - wxScopeGuardImplBase(const wxScopeGuardImplBase& other) - : m_wasDismissed(other.m_wasDismissed) - { - other.Dismiss(); - } - // must be mutable for copy ctor to work mutable bool m_wasDismissed; @@ -86,6 +116,9 @@ private: wxScopeGuardImplBase& operator=(const wxScopeGuardImplBase&); }; +// wxScopeGuard is just a reference, see the explanation in CUJ article +typedef const wxScopeGuardImplBase& wxScopeGuard; + // ---------------------------------------------------------------------------- // wxScopeGuardImpl0: scope guard for actions without parameters // ---------------------------------------------------------------------------- @@ -99,7 +132,7 @@ public: return wxScopeGuardImpl0(fun); } - ~wxScopeGuardImpl0() { wxPrivate::OnScopeExit(*this); } + ~wxScopeGuardImpl0() { wxPrivateOnScopeExit(*this); } void Execute() { m_fun(); } @@ -130,7 +163,7 @@ public: return wxScopeGuardImpl1(fun, p1); } - ~wxScopeGuardImpl1() { wxPrivate::OnScopeExit(*this); } + ~wxScopeGuardImpl1() { wxPrivateOnScopeExit(* this); } void Execute() { m_fun(m_p1); } @@ -162,7 +195,7 @@ public: return wxScopeGuardImpl2(fun, p1, p2); } - ~wxScopeGuardImpl2() { wxPrivate::OnScopeExit(*this); } + ~wxScopeGuardImpl2() { wxPrivateOnScopeExit(*this); } void Execute() { m_fun(m_p1, m_p2); } @@ -182,6 +215,41 @@ inline wxScopeGuardImpl2 wxMakeGuard(F fun, P1 p1, P2 p2) return wxScopeGuardImpl2::MakeGuard(fun, p1, p2); } +// ---------------------------------------------------------------------------- +// wxScopeGuardImpl3: scope guard for actions with 3 parameters +// ---------------------------------------------------------------------------- + +template +class wxScopeGuardImpl3 : public wxScopeGuardImplBase +{ +public: + static wxScopeGuardImpl3 MakeGuard(F fun, P1 p1, P2 p2, P3 p3) + { + return wxScopeGuardImpl3(fun, p1, p2, p3); + } + + ~wxScopeGuardImpl3() { wxPrivateOnScopeExit(*this); } + + void Execute() { m_fun(m_p1, m_p2, m_p3); } + +protected: + wxScopeGuardImpl3(F fun, P1 p1, P2 p2, P3 p3) + : m_fun(fun), m_p1(p1), m_p2(p2), m_p3(p3) { } + + F m_fun; + const P1 m_p1; + const P2 m_p2; + const P3 m_p3; + + wxScopeGuardImpl3& operator=(const wxScopeGuardImpl3&); +}; + +template +inline wxScopeGuardImpl3 wxMakeGuard(F fun, P1 p1, P2 p2, P3 p3) +{ + return wxScopeGuardImpl3::MakeGuard(fun, p1, p2, p3); +} + // ============================================================================ // wxScopeGuards for object methods // ============================================================================ @@ -200,7 +268,7 @@ public: return wxObjScopeGuardImpl0(obj, memFun); } - ~wxObjScopeGuardImpl0() { wxPrivate::OnScopeExit(*this); } + ~wxObjScopeGuardImpl0() { wxPrivateOnScopeExit(*this); } void Execute() { (m_obj.*m_memfun)(); } @@ -228,7 +296,7 @@ public: return wxObjScopeGuardImpl1(obj, memFun, p1); } - ~wxObjScopeGuardImpl1() { wxPrivate::OnScopeExit(*this); } + ~wxObjScopeGuardImpl1() { wxPrivateOnScopeExit(*this); } void Execute() { (m_obj.*m_memfun)(m_p1); } @@ -258,7 +326,7 @@ public: return wxObjScopeGuardImpl2(obj, memFun, p1, p2); } - ~wxObjScopeGuardImpl2() { wxPrivate::OnScopeExit(*this); } + ~wxObjScopeGuardImpl2() { wxPrivateOnScopeExit(*this); } void Execute() { (m_obj.*m_memfun)(m_p1, m_p2); } @@ -280,56 +348,204 @@ wxMakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2) MakeObjGuard(obj, memFun, p1, p2); } +template +class wxObjScopeGuardImpl3 : public wxScopeGuardImplBase +{ +public: + static wxObjScopeGuardImpl3 + MakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2, P3 p3) + { + return wxObjScopeGuardImpl3(obj, memFun, p1, p2, p3); + } + + ~wxObjScopeGuardImpl3() { wxPrivateOnScopeExit(*this); } + + void Execute() { (m_obj.*m_memfun)(m_p1, m_p2, m_p3); } + +protected: + wxObjScopeGuardImpl3(Obj& obj, MemFun memFun, P1 p1, P2 p2, P3 p3) + : m_obj(obj), m_memfun(memFun), m_p1(p1), m_p2(p2), m_p3(p3) { } + + Obj& m_obj; + MemFun m_memfun; + const P1 m_p1; + const P2 m_p2; + const P3 m_p3; +}; + +template +inline wxObjScopeGuardImpl3 +wxMakeObjGuard(Obj& obj, MemFun memFun, P1 p1, P2 p2, P3 p3) +{ + return wxObjScopeGuardImpl3:: + MakeObjGuard(obj, memFun, p1, p2, p3); +} + +// ---------------------------------------------------------------------------- +// wxVariableSetter: use the same technique as for wxScopeGuard to allow +// setting a variable to some value on block exit +// ---------------------------------------------------------------------------- + +namespace wxPrivate +{ + +// empty class just to be able to define a reference to it +class VariableSetterBase : public wxScopeGuardImplBase { }; + +typedef const VariableSetterBase& VariableSetter; + +template +class VariableSetterImpl : public VariableSetterBase +{ +public: + VariableSetterImpl(T& var, U value) + : m_var(var), + m_value(value) + { + } + + ~VariableSetterImpl() { wxPrivateOnScopeExit(*this); } + + void Execute() { m_var = m_value; } + +private: + T& m_var; + const U m_value; + + // suppress the warning about assignment operator not being generated + VariableSetterImpl& operator=(const VariableSetterImpl&); +}; + +template +class VariableNullerImpl : public VariableSetterBase +{ +public: + VariableNullerImpl(T& var) + : m_var(var) + { + } + + ~VariableNullerImpl() { wxPrivateOnScopeExit(*this); } + + void Execute() { m_var = NULL; } + +private: + T& m_var; + + VariableNullerImpl& operator=(const VariableNullerImpl&); +}; + +} // namespace wxPrivate + +template +inline +wxPrivate::VariableSetterImpl wxMakeVarSetter(T& var, U value) +{ + return wxPrivate::VariableSetterImpl(var, value); +} + +// calling wxMakeVarSetter(ptr, NULL) doesn't work because U is deduced to be +// "int" and subsequent assignment of "U" to "T *" fails, so provide a special +// function for this special case +template +inline +wxPrivate::VariableNullerImpl wxMakeVarNuller(T& var) +{ + return wxPrivate::VariableNullerImpl(var); +} + // ============================================================================ -// public stuff +// macros for declaring unnamed scoped guards (which can't be dismissed) // ============================================================================ -// wxScopeGuard is just a reference, see the explanation in CUJ article -typedef const wxScopeGuardImplBase& wxScopeGuard; - -// when an unnamed scope guard is needed, the macros below may be used -// // NB: the original code has a single (and much nicer) ON_BLOCK_EXIT macro // but this results in compiler warnings about unused variables and I // didn't find a way to work around this other than by having different -// macros with different names +// macros with different names or using a less natural syntax for passing +// the arguments (e.g. as Boost preprocessor sequences, which would mean +// having to write wxON_BLOCK_EXIT(fwrite, (buf)(size)(n)(fp)) instead of +// wxON_BLOCK_EXIT4(fwrite, buf, size, n, fp)). -#define wxGuardName wxMAKE_UNIQUE_NAME(scopeGuard) +#define wxGuardName wxMAKE_UNIQUE_NAME(wxScopeGuard) #define wxON_BLOCK_EXIT0_IMPL(n, f) \ wxScopeGuard n = wxMakeGuard(f); \ - wxPrivate::Use(n) + wxPrivateUse(n) #define wxON_BLOCK_EXIT0(f) \ wxON_BLOCK_EXIT0_IMPL(wxGuardName, f) #define wxON_BLOCK_EXIT_OBJ0_IMPL(n, o, m) \ wxScopeGuard n = wxMakeObjGuard(o, m); \ - wxPrivate::Use(n) + wxPrivateUse(n) #define wxON_BLOCK_EXIT_OBJ0(o, m) \ - wxON_BLOCK_EXIT_OBJ0_IMPL(wxGuardName, o, m) + wxON_BLOCK_EXIT_OBJ0_IMPL(wxGuardName, o, &m) + +#define wxON_BLOCK_EXIT_THIS0(m) \ + wxON_BLOCK_EXIT_OBJ0(*this, m) + #define wxON_BLOCK_EXIT1_IMPL(n, f, p1) \ wxScopeGuard n = wxMakeGuard(f, p1); \ - wxPrivate::Use(n) + wxPrivateUse(n) #define wxON_BLOCK_EXIT1(f, p1) \ wxON_BLOCK_EXIT1_IMPL(wxGuardName, f, p1) #define wxON_BLOCK_EXIT_OBJ1_IMPL(n, o, m, p1) \ wxScopeGuard n = wxMakeObjGuard(o, m, p1); \ - wxPrivate::Use(n) + wxPrivateUse(n) #define wxON_BLOCK_EXIT_OBJ1(o, m, p1) \ - wxON_BLOCK_EXIT_OBJ1_IMPL(wxGuardName, o, m, p1) + wxON_BLOCK_EXIT_OBJ1_IMPL(wxGuardName, o, &m, p1) + +#define wxON_BLOCK_EXIT_THIS1(m, p1) \ + wxON_BLOCK_EXIT_OBJ1(*this, m, p1) + #define wxON_BLOCK_EXIT2_IMPL(n, f, p1, p2) \ wxScopeGuard n = wxMakeGuard(f, p1, p2); \ - wxPrivate::Use(n) + wxPrivateUse(n) #define wxON_BLOCK_EXIT2(f, p1, p2) \ wxON_BLOCK_EXIT2_IMPL(wxGuardName, f, p1, p2) #define wxON_BLOCK_EXIT_OBJ2_IMPL(n, o, m, p1, p2) \ wxScopeGuard n = wxMakeObjGuard(o, m, p1, p2); \ - wxPrivate::Use(n) + wxPrivateUse(n) #define wxON_BLOCK_EXIT_OBJ2(o, m, p1, p2) \ - wxON_BLOCK_EXIT_OBJ2_IMPL(wxGuardName, o, m, p1, p2) + wxON_BLOCK_EXIT_OBJ2_IMPL(wxGuardName, o, &m, p1, p2) + +#define wxON_BLOCK_EXIT_THIS2(m, p1, p2) \ + wxON_BLOCK_EXIT_OBJ2(*this, m, p1, p2) + + +#define wxON_BLOCK_EXIT3_IMPL(n, f, p1, p2, p3) \ + wxScopeGuard n = wxMakeGuard(f, p1, p2, p3); \ + wxPrivateUse(n) +#define wxON_BLOCK_EXIT3(f, p1, p2, p3) \ + wxON_BLOCK_EXIT3_IMPL(wxGuardName, f, p1, p2, p3) + +#define wxON_BLOCK_EXIT_OBJ3_IMPL(n, o, m, p1, p2, p3) \ + wxScopeGuard n = wxMakeObjGuard(o, m, p1, p2, p3); \ + wxPrivateUse(n) +#define wxON_BLOCK_EXIT_OBJ3(o, m, p1, p2, p3) \ + wxON_BLOCK_EXIT_OBJ3_IMPL(wxGuardName, o, &m, p1, p2, p3) + +#define wxON_BLOCK_EXIT_THIS3(m, p1, p2, p3) \ + wxON_BLOCK_EXIT_OBJ3(*this, m, p1, p2, p3) + + +#define wxSetterName wxMAKE_UNIQUE_NAME(wxVarSetter) + +#define wxON_BLOCK_EXIT_SET_IMPL(n, var, value) \ + wxPrivate::VariableSetter n = wxMakeVarSetter(var, value); \ + wxPrivateUse(n) + +#define wxON_BLOCK_EXIT_SET(var, value) \ + wxON_BLOCK_EXIT_SET_IMPL(wxSetterName, var, value) + +#define wxON_BLOCK_EXIT_NULL_IMPL(n, var) \ + wxPrivate::VariableSetter n = wxMakeVarNuller(var); \ + wxPrivateUse(n) + +#define wxON_BLOCK_EXIT_NULL(ptr) \ + wxON_BLOCK_EXIT_NULL_IMPL(wxSetterName, ptr) #endif // _WX_SCOPEGUARD_H_