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 float .............. Builtin basic type double ............. Builtin basic type void ............... Builtin basic type Char_t ............. Signed Character 1 byte (char) UChar_t ............ Unsigned Character 1 byte (unsigned char) Short_t ............ Signed Short integer 2 bytes (short) UShort_t ........... Unsigned Short integer 2 bytes (unsigned short) Int_t .............. Signed integer 4 bytes (int) UInt_t ............. Unsigned integer 4 bytes (unsigned int) Seek_t ............. File pointer (int) Long_t ............. Signed long integer 4 bytes (long) ULong_t ............ Unsigned long integer 4 bytes (unsigned long) Float_t ............ Float 4 bytes (float) Double_t ........... Float 8 bytes (double) Text_t ............. General string (char) Bool_t ............. Boolean (0=false, 1=true) (unsigned char) Byte_t ............. Byte (8 bits) (unsigned char) Version_t .......... Class version identifier (short) Option_t ........... Option string (const char) Ssiz_t ............. String size (int) Real_t ............. TVector and TMatrix element type (float) VoidFuncPtr_t ...... pointer to void function Axis_t ............. Axis values type (double) Stat_t ............. Statistics type (double) TSeqCol ............ Statistics type (double) ErrorHandlerFunc_t . Statistics type (double) Font_t ............. Font number (short) Style_t ............ Style number (short) Marker_t ........... Marker number (short) Width_t ............ Line width (short) Color_t ............ Color number (short) SCoord_t ........... Screen coordinates (short) Coord_t ............ Pad world coordinates (double) Angle_t ............ Graphics angle (float) Size_t ............. Attribute size (float) Size3D ............. Attribute size (float) SigHandler_t ....... Statistics type (double) SecureAuth_t ....... Statistics type (double) TWin32SendClass .... Statistics type (double) Handle_t ........... Generic resource handle Display_t .......... Display handle Window_t ........... Window 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) KeySym_t ........... Key symbol handle Atom_t ............. WM token GContext_t ......... Graphics context handle (or pointer, needs to be long) FontStruct_t ....... Pointer to font structure Mask_t ............. Structure mask type Time_t ............. Event time size_t ............. Event time