\documentclass{article}

% check no hyphenation in verb
% based on tlb-verb-001.lvt (latex2e r1405)

\parindent0pt
\parskip10pt
\textwidth10pt

\makeatletter
\def\verbatim@font{\normalfont\rmfamily}
\makeatother

\begin{document}

ハイフネーションが起きないかどうかテスト。

1 elephant tortoise

2 \verb|elephant tortoise|

\verb|elephant tortoise|

\end{document}


%% LaTeX original
\def\verb{\relax\ifmmode\hbox\else\leavevmode\null\fi
  \bgroup
    \verb@eol@error \let\do\@makeother \dospecials
    \verbatim@font\@noligs
    \@ifstar\@sverb\@verb}
%% LaTeX (2017-04-15 candidate)
\def\verb{\relax\ifmmode\hbox\else\leavevmode\null\fi
  \bgroup
    \verb@eol@error \let\do\@makeother \dospecials
    \verbatim@font\@noligs
    \language\l@nohyphenation
    \@ifstar\@sverb\@verb}
%% pLaTeX (ASCII)
\def\verb{\relax\ifmmode\hbox\else\leavevmode\fi
  \bgroup
    \verb@eol@error \let\do\@makeother \dospecials
    \verbatim@font\@noligs
    \@ifstar\@sverb\@verb}
%% pLaTeX (2017/04/08)
\def\verb{\relax\ifmmode\hbox\else\leavevmode\fi
  \bgroup
    \verb@eol@error \let\do\@makeother \dospecials
    \verbatim@font\@noligs
    \language\l@nohyphenation
    \@ifstar\@sverb\@verb}
%% pLaTeX (candidate)
\def\verb{\relax\ifmmode\hbox\else\leavevmode\vadjust{}\fi
  \bgroup
    \verb@eol@error \let\do\@makeother \dospecials
    \verbatim@font\@noligs
    \language\l@nohyphenation
    \@ifstar\@sverb\@verb}
