Quotations around the letter t: csquotes

Question

MWE:

\documentclass[12pt]{article}

%make " quotation marks 
\usepackage[english]{babel}
\usepackage{csquotes}
\MakeOuterQuote{"}

\begin{document}
\texttt{read.table(file, sep = "t")}
\end{document}

The desired output should be obvious from the code above. The output from this is the following:

Answer 1

The character " is made active, to expand to a double opening or closing quote (context depending). However, the typewriter font in OT1 encoding has a backslash where the text fonts have the double opening quote.

Solution:

\documentclass[12pt]{article}
%make " quotation marks
\usepackage[english]{babel}
\usepackage{csquotes}
\MakeOuterQuote{"}

\begingroup\lccode`~=`"
\lowercase{\endgroup
  \DeclareTextFontCommand{\texttt}{\ttfamily\def~{"}}%
}

\begin{document}
\texttt{read.table(file, sep = "t")}
\end{document}

This won't work if you nest quoted text in normal font inside \texttt. It won't work also in the scope of \ttfamily, but it could be arranged for.