Conditionally include attribute in XML literal

I have the following XML literal:

<input type='radio'
       name={funcName}
       value='true' />

I'd like to include checked='checked' if cond is true.

I've tried this,

<input type='radio'
       name={funcName}
       value='true'
       { if (cond) "checked='checked'" else "" } />

but it doesn't work.

(I'd really like to avoid repeating the whole tag.)