maint: Use macros to begin/end C++ namespaces. * BaseControl.cc, BaseControl.h, ButtonControl.cc, ButtonControl.h, ButtonGroup.cc, ButtonGroup.h, Canvas.cc, Canvas.h, CheckBoxControl.cc, CheckBoxControl.h, Container.cc, Container.h, ContextMenu.cc, ContextMenu.h, EditControl.cc, EditControl.h, Figure.cc, Figure.h, FigureWindow.cc, FigureWindow.h, GLCanvas.cc, GLCanvas.h, GenericEventNotify.h, KeyMap.cc, KeyMap.h, ListBoxControl.cc, ListBoxControl.h, Logger.cc, Logger.h, Menu.cc, Menu.h, MenuContainer.h, Object.cc, Object.h, ObjectProxy.cc, ObjectProxy.h, Panel.cc, Panel.h, PopupMenuControl.cc, PopupMenuControl.h, PushButtonControl.cc, PushButtonControl.h, PushTool.cc, PushTool.h, QtHandlesUtils.cc, QtHandlesUtils.h, RadioButtonControl.cc, RadioButtonControl.h, SliderControl.cc, SliderControl.h, Table.cc, Table.h, TextControl.cc, TextControl.h, TextEdit.cc, TextEdit.h, ToggleButtonControl.cc, ToggleButtonControl.h, ToggleTool.cc, ToggleTool.h, ToolBar.cc, ToolBar.h, ToolBarButton.cc, ToolBarButton.h, annotation-dialog.cc, annotation-dialog.h, gl-select.cc, gl-select.h, qopengl-functions.h, qt-graphics-toolkit.cc, qt-graphics-toolkit.h, QTerminal.h, color-picker.cc, color-picker.h, command-widget.cc, command-widget.h, community-news.cc, community-news.h, dialog.cc, dialog.h, documentation-bookmarks.cc, documentation-bookmarks.h, documentation-dock-widget.cc, documentation-dock-widget.h, documentation.cc, documentation.h, dw-main-window.cc, dw-main-window.h, external-editor-interface.cc, external-editor-interface.h, files-dock-widget.cc, files-dock-widget.h, find-files-dialog.cc, find-files-dialog.h, find-files-model.cc, find-files-model.h, graphics-init.cc, graphics-init.h, gui-settings.cc, gui-settings.h, gui-utils.cc, gui-utils.h, history-dock-widget.cc, history-dock-widget.h, interpreter-qobject.cc, interpreter-qobject.h, led-indicator.cc, led-indicator.h, file-editor-interface.h, file-editor-tab.cc, file-editor-tab.h, file-editor.cc, file-editor.h, find-dialog.cc, find-dialog.h, marker.cc, marker.h, octave-qscintilla.cc, octave-qscintilla.h, octave-txt-lexer.cc, octave-txt-lexer.h, main-window.cc, main-window.h, news-reader.cc, news-reader.h, octave-dock-widget.cc, octave-dock-widget.h, octave-qobject.cc, octave-qobject.h, qt-application.cc, qt-application.h, qt-interpreter-events.cc, qt-interpreter-events.h, qt-utils.h, release-notes.cc, release-notes.h, resource-manager.cc, resource-manager.h, set-path-dialog.cc, set-path-dialog.h, set-path-model.cc, set-path-model.h, settings-dialog.cc, settings-dialog.h, shortcut-manager.cc, shortcut-manager.h, tab-bar.cc, tab-bar.h, terminal-dock-widget.cc, terminal-dock-widget.h, variable-editor-model.cc, variable-editor-model.h, variable-editor.cc, variable-editor.h, welcome-wizard.cc, welcome-wizard.h, workspace-model.cc, workspace-model.h, workspace-view.cc, workspace-view.h: Use new macros to begin/end C++ namespaces.

## INLINE contstructor

%!shared fn
%! fn = inline ("x.^2 + 1");
%!assert (feval (fn, 6), 37)
%!assert (fn (6), 37)
%!assert (feval (inline ("sum (x(:))"), [1 2; 3 4]), 10)
%!assert (feval (inline ("sqrt (x^2 + y^2)", "x", "y"), 3, 4), 5)
%!assert (feval (inline ("exp (P1*x) + P2", 3), 3, 4, 5), exp (3*4) + 5)

## Test input validation
%!error inline ()
%!error <EXPR must be a string> inline (1)
%!error <N must be an integer> inline ("2", ones (2,2))
%!error <N must be a positive integer> inline ("2", -1)
%!error <additional arguments must be strings> inline ("2", "x", -1, "y")

## FORMULA

%!assert (formula (fn), "x.^2 + 1")
%!assert (formula (fn), char (fn))

## ARGNAMES

%!assert (argnames (fn), {"x"})
%!assert (argnames (inline ("1e-3*y + 2e4*z")), {"y"; "z"})
%!assert (argnames (inline ("2", 2)), {"x"; "P1"; "P2"})

## VECTORIZE

%!assert (formula (vectorize (fn)), "x.^2 + 1")
%!assert (formula (vectorize (inline ("1e-3*y + 2e4*z"))), "1e-3.*y + 2e4.*z")
%!assert (formula (vectorize (inline ("2^x^5"))), "2.^x.^5")