# How create 1 overlapped by a tilde in math mode?

I've invented a custom symbol I wish to use in my LaTeX writings. It is a one, 1, overlapped with a tilde. This image shows what I want:

The actual symbol for the tilde is \sim. I have seen \rlap used to make characters overlap, as in

$\rlap{X}O$


which creates

but when I try

$\rlap{\sim}{1}$


}%
% place the tilde raised to the correct height
\raise\dimexpr.5\ht2 - \ht4\relax\copy0 %
}
\makeatother

\begin{document}
$1 + {\sim} = \tildeone$
\end{document}


Here are three solutions, based on \mathclap from \mathtools and \stackinset from stackengine:

\documentclass[12pt]{article}
\usepackage{mathtools}
\usepackage{stackengine}

\begin{document}

$\mathclap {1}\mathclap{\sim}\qquad \mathclap {1}\mathclap{\raisebox{0.1ex}{ \sim }}\qquad \stackinset{c}{0pt}{c}{-0.2ex}{ \sim }{ 1 }$%

\end{document}