... text   FooFactory::
instance()->createFoo()

FooFactory::instance()->
createFoo() text text ...

documentclass{article}
usepackage[utf8]{inputenc}
usepackage[left=6cm,right=7cm]{geometry}
usepackage{parskip}
usepackage{showframe}
usepackage{listings}

lstset{
    language=C++,
    basicstyle=ttfamily,
    breaklines=true,
    breakatwhitespace=true,
    inputencoding=utf8,
    extendedchars=true
}
lstset{literate=% I dont know what I am doing...
    {::}{::}{1discretionary{}{}{}} % line-break at ::
    {->}{->}{1discretionary{}{}{}} % line-break at ->
}

begin{document}

text text text text text text text text lstinline{FooFactory::instance()->createFoo()} text text
text text text text

text text text text text text lstinline{FooFactory::instance()->createFoo()} text text
text text text text

end{document}