Allow dispatch on second argument

This PR makes the following legal

@with_signature [legacy=false] myfunc(eq::Equation, mesh::Mesh1d)
   @accepts u
   v = u
   @returns v
end

added feature label

added 1 commit

• 91179723 - add unit test

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added 3 commits

• 1ccef689 - fix docs
• 6ef8c687 - remove debug statement
• 3eecb6f1 - enable mesh argument in broadcasting methods

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merged

mentioned in commit e28a6d01

mentioned in commit 236a24d5