OpenType font supports all styles, one font file?

Fonts and More Specification
1

Does this exist -
an OpenType font that supports all four styles (PLAIN, BOLD, ITALIC, BOLD_ITALIC) in one font file?

I would like examples of

  1. Open Type font in TT outline, .ttf extension
  2. Open Type font in Type 1 (PostScript), .otf extension
  3. Open Type font in TT outline, .oft extension (not sure this one makes sense).

Thanks

2

This is not possible as far as I know, but see this thread on TTC files.

3

Thank you for your answer, Bhikkhu.
B