char ......................................... Builtin basic type unsigned char ................................ Builtin basic type short ........................................ Builtin basic type unsigned short ............................... Builtin basic type int .......................................... Builtin basic type unsigned int ................................. Builtin basic type long ......................................... Builtin basic type unsigned long ................................ Builtin basic type long long .................................... Builtin basic type unsigned long long ........................... Builtin basic type float ........................................ Builtin basic type double ....................................... Builtin basic type void ......................................... Builtin basic type bool ......................................... Builtin basic type Int_t ........................................ Signed integer 4 bytes (int) UInt_t ....................................... Unsigned integer 4 bytes (unsigned int) Long_t ....................................... Signed long integer 4 bytes (long) Float_t ...................................... Float 4 bytes (float) Bool_t ....................................... Boolean (0=false, 1=true) (bool) Version_t .................................... Class version identifier (short) Option_t ..................................... Option string (const char) ULong_t ...................................... Unsigned long integer 4 bytes (unsigned long) Double_t ..................................... Double 8 bytes Window_t ..................................... Window handle Font_t ....................................... Font number (short) UChar_t ...................................... Unsigned Character 1 byte (unsigned char) Short_t ...................................... Signed Short integer 2 bytes (short) Style_t ...................................... Style number (short) Width_t ...................................... Line width (short) Color_t ...................................... Color number (short) Handle_t ..................................... Generic resource handle Display_t .................................... Display handle Visual_t ..................................... Visual handle Pixmap_t ..................................... Pixmap handle Drawable_t ................................... Drawable handle Region_t ..................................... Region handle Colormap_t ................................... Colormap handle Cursor_t ..................................... Cursor handle FontH_t ...................................... Font handle (as opposed to Font_t which is an index) Atom_t ....................................... WM token GContext_t ................................... Graphics context handle FontStruct_t ................................. Pointer to font structure Mask_t ....................................... Structure mask type Time_t ....................................... Event time Pixel_t ...................................... Pixel value Long64_t ..................................... Portable signed long integer 8 bytes Size_t ....................................... Attribute size (float) Char_t ....................................... Signed Character 1 byte (char) TThread::VoidRtnFunc_t ....................... void *(*VoidRtnFunc_t)(void *); TThread::VoidFunc_t .......................... void (*VoidFunc_t)(void *); VoidFuncPtr_t ................................ pointer to void function ShowMembersFunc_t ............................ void (*ShowMembersFunc_t)(void *obj, TMemberInspector &R__insp, char *R__parent); IsAFunc_t .................................... TClass *(*IsAFunc_t)(const void *obj); ROOT::NewFunc_t .............................. void *(*NewFunc_t)(void *); ROOT::NewArrFunc_t ........................... void *(*NewArrFunc_t)(Long_t size); ROOT::DelFunc_t .............................. void (*DelFunc_t)(void *); ROOT::DelArrFunc_t ........................... void (*DelArrFunc_t)(void *); ROOT::DesFunc_t .............................. void (*DesFunc_t)(void *); ROOT::TBranchProxyClassDescriptor::EInClones . for IsClones Axis_t ....................................... Axis values type (double) Text_t ....................................... General string (char) TPainter3dAlgorithms::DrawFaceFunc_t ......... void (TPainter3dAlgorithms::*DrawFaceFunc_t)(Int_t *, Double_t *, Int_t, Int_t *, Double_t *); TPainter3dAlgorithms::LegoFunc_t ............. void (TPainter3dAlgorithms::*LegoFunc_t)(Int_t,Int_t,Int_t&,Double_t*,Double_t*,Double_t*); TPainter3dAlgorithms::SurfaceFunc_t .......... void (TPainter3dAlgorithms::*SurfaceFunc_t)(Int_t,Int_t,Double_t*,Double_t*); Stat_t ....................................... Statistics type (double) Marker_t ..................................... Marker number (short) UShort_t ..................................... Unsigned Short integer 2 bytes (unsigned short) ULong64_t .................................... Portable unsigned long integer 8 bytes CheckSecCtx_t ................................ Int_t (*CheckSecCtx_t)(const char *subj, TSecContext *ctx); GlobusAuth_t ................................. Int_t (*GlobusAuth_t)(TAuthenticate *auth, TString &user, TString &det); Krb5Auth_t ................................... Int_t (*Krb5Auth_t)(TAuthenticate *auth, TString &user, TString &det, Int_t version); SecureAuth_t ................................. Int_t (*SecureAuth_t)(TAuthenticate *auth, const char *user, const char *passwd, MemberStreamerFunc_t ......................... Streamer function for a data member IsAGlobalFunc_t .............................. TClass *(*IsAGlobalFunc_t)(const TClass*, const void *obj); TAssoc ....................................... for backward compatibility KeySym_t ..................................... Key symbol handle Ssiz_t ....................................... String size (int) FreeHookFun_t ................................ void (*FreeHookFun_t)(void*, void *addr, size_t); ReAllocFun_t ................................. void *(*ReAllocFun_t)(void*, size_t); ReAllocCFun_t ................................ void *(*ReAllocCFun_t)(void*, size_t, size_t); SCoord_t ..................................... Screen coordinates (short) Double32_t ................................... Double 8 bytes in memory, written as a 4 bytes float ios_base::event_callback ..................... void (*event_callback) (event, ios_base&, int index);