Make an X selection of type TYPE and value DATA.
The argument TYPE (nil means `PRIMARY') says which selection, and
DATA specifies the contents. TYPE must be a symbol. (It can also
be a string, which stands for the symbol with that name, but this
is considered obsolete.) DATA may be a string, a symbol, an
integer (or a cons of two integers or list of two integers).
The selection may also be a cons of two markers pointing to the same buffer,
or an overlay. In these cases, the selection is considered to be the text
between the markers *at whatever time the selection is examined*.
Thus, editing done in the buffer after you specify the selection
can alter the effective value of the selection.
The data may also be a vector of valid non-vector selection values.
The return value is DATA.
Interactively, this command sets the primary selection. Without
prefix argument, it reads the selection in the minibuffer. With
prefix argument, it uses the text of the region as the selection value.
Note that on MS-Windows, primary and secondary selections set by Emacs
are not available to other programs.