How to get vertical quotes by default with tt fonts?

Question

I would like to always get vertical quotes for ' and " when using the tt font. I can get that with the upquote package for verbatim environments, and with the macros provided by textcomp, but I would also like it to be the default for \texttt and \ttfamily.

\documentclass{article}
\usepackage{textcomp, upquote}
\begin{document}
\verb|This is a vertical quote: '|

\texttt{I wish this were a vertical quote: '
(like this one: \textquotesingle)}
\end{document}

Is there a way to do that? And let me add, with pdflatex, before someone suggests some remapping command that only works with xelatex/lualatex.

Edit: I have succeeded in implementing a solution via Heiko Oberdiek's lm-ec-tt.map method, at least via the \pdfmapfile command. (I have not yet tried to put the modified .map and .enc files in my ~/texmf area.)

But I also succeeded in getting \ttfamily redefined, which is a path I think I'd prefer. Unfortunately, \texttt still doesn't work. In my (obviously wrong) understanding of the code in article.cls, \texttt should be defined in terms of \ttfamily. So why doesn't the following work for \texttt?:

\documentclass{article}
\usepackage{textcomp, upquote}

\makeatletter
\renewcommand\ttfamily
        {\not@math@alphabet\ttfamily\mathtt
         \fontfamily\ttdefault\selectfont
         \@noligs}% all I do is add this
\makeatother

\begin{document}
\texttt{texttt: quote:'; doublequote:"; grave:`}\par      % doesn't work
{\ttfamily ttfamily: quote:'; doublequote:"; grave:`}\par % works
\verb| verb: quote:'; doublequote:"; grave:`|\par
\end{document}

Answer 1

LuaTeX

If LuaTeX or XeTeX is an option, then the default font of package fontspec uses the Latin Modern fonts (the successors of the Computer Modern fonts). There, the single and double quote are plain vertical:

\documentclass{article}
\usepackage{fontspec}
\begin{document}
\verb|These are vertical quotes: ' and "|

\texttt{These are vertical quotes: ' and "}

\texttt{These are vertical quotes: \textquotesingle\ and \textquotedbl}
\end{document}

XeTeX

XeTeX also work, but the spacing is different, because it respects the space factor settings better that are active in \texttt in opposite to \verb that automatically sets \frenchspacing.

pdfTeX

A clean solution for pdfTeX would be to change the encoding of the typewriter font to replace the single quote. The map file entries look like:

ec-lmtt10 LMMono10-Regular " enclmec ReEncodeFont " <lm-ec.enc <lmtt10.pfb

The encoding is defined in file lm-ec.enc. It can be located via:

kpsewhich lm-ec.enc

This file can be copied to lm-ec-tt.enc, which replaces /quotesingleright by /quotesingle:

...
/ampersand
/quotesingle
/parenleft
...

Then a map file lm-ec-tt.map for the affected fonts can be created that uses the new encoding file lm-ec-tt.enc:

ec-lmtt10 LMMono10-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmtt10.pfb
ec-lmtt12 LMMono12-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmtt12.pfb
ec-lmtt8 LMMono8-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmtt8.pfb
ec-lmtt9 LMMono9-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmtt9.pfb
ec-lmtti10 LMMono10-Italic " enclmec ReEncodeFont " <lm-ec-tt.enc <lmtti10.pfb
ec-lmtto10 LMMonoSlant10-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmtto10.pfb
ec-lmvtk10 LMMonoPropLt10-Bold " enclmec ReEncodeFont " <lm-ec-tt.enc <lmvtk10.pfb
ec-lmvtko10 LMMonoPropLt10-BoldOblique " enclmec ReEncodeFont " <lm-ec-tt.enc <lmvtko10.pfb
ec-lmvtl10 LMMonoPropLt10-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmvtl10.pfb
ec-lmvtlo10 LMMonoPropLt10-Oblique " enclmec ReEncodeFont " <lm-ec-tt.enc <lmvtlo10.pfb
ec-lmvtt10 LMMonoProp10-Regular " enclmec ReEncodeFont " <lm-ec-tt.enc <lmvtt10.pfb
ec-lmvtto10 LMMonoProp10-Oblique " enclmec ReEncodeFont " <lm-ec-tt.enc <lmvtto10.pfb

Then the pdfTeX document starts at the very beginning with the replacement of these fonts: \pdfmapfile{=lm-ec-tt.map}

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{lmodern}
\usepackage{textcomp}
\begin{document}
\verb|These are vertical quotes: ' and "|

\texttt{These are vertical quotes: ' and "}

\texttt{These are vertical quotes: \textquotesingle\ and \textquotedbl}
\end{document}

The trick via the map and encoding file works for this case, because the bounding boxes of the symbols that are exchanged are the same.