With generated code, it's common to end up troubleshooting code such as
(apologies for bad formatting due to phone UI)

struct field1 { int i{ 4} ;};

struct field2 {double d{3.142};};

struct msg
{
field1 f1;
field2 f2;

field1& fielder() { return f1;}
field1 const& fielder() const { return f1;}
} ;

field1 getter( msg in)
{
return in. fielder() ;
}

int main()
{
msg m;
return getter) m) ;
}

Depending on exactly how everything gets cv a ualified, the results can be interesting, and difficult to reason about.

A great help would be to be able to see the types used by the compiler at each call point. Especially now with varying materialization fules depending on language version.