\pgflinewidth as option in arrows.meta arrows heads

i try to define arrow's head size by using ˙\pgflinewidth:

\documentclass[tikz,margin=3mm]{standalone}
\usetikzlibrary{arrows.meta, calc}

\begin{document}
\begin{tikzpicture}
\draw (0cm,0cm) grid ($(2cm,3cm)-(\pgflinewidth,\pgflinewidth)$);       % this works

\draw[very thick, -{Triangle[length=3\pgflinewidth]}] (0,0) -- (2,3);   % this doesn't work!
\end{tikzpicture}
\end{document}


error: ! Missing \endcsname inserted..

what is wrong in my attempt?

Try:

Triangle[length=3*\the\pgflinewidth]


MWE

\documentclass[tikz,margin=3mm]{standalone}
\usetikzlibrary{arrows.meta, calc}
\begin{document}
\begin{tikzpicture}
\draw (0cm,0cm) grid ($(2cm,3cm)-(\pgflinewidth,\pgflinewidth)$);       % this works

\draw[very thick, -{Triangle[length=3*\the\pgflinewidth]}] (0,0) -- (2,3);   % this doesn't work!
\end{tikzpicture}
\end{document}


EDIT

The same output can be obtained with the following line also:

\draw[very thick, -{Triangle[length=0pt 3]}] (0,0) -- (2,3);

• May be a bit of an explanation would add great value to this answer! – Raaja Dec 5 '18 at 9:37
• this solution not cause error, however, arrows head is far to big (about 8 times). this means that it not consider width of used rule. – Zarko Dec 5 '18 at 9:40
• @Zarko I don't know why it is like that. But replacing 3\the\pgflinewidth with 3*\the\pgflinewidth seems to solve the problem. – nidhin Dec 5 '18 at 9:51
• @nidhin, thank you very much. now works correctly.. – Zarko Dec 5 '18 at 13:20
• @Zarko You can actually use Triangle[length=0pt 3]` to get the desired output. – nidhin Dec 5 '18 at 13:26