Having the prototype available before the first use of the function allows the compiler to check that the correct number and type of arguments are used in the function call and that the returned value, if any, is being used reasonably. The function definition itself can act as an implicit function declaration.
While shellac is not usually the finish paint choice, it is often thought of as the best paint primer available. It has properties that oil and water based paints can't match, and provides a more dependable seal than most other primers are able to provide.
Once T1-111 starts to delaminate it is time to replace it as it will just keep on doing it. You have found out first hand why you don't prime large exterior areas with shellac. You prime T1-111 with an exterior acrylic primer and finish with acrylic house paint in a flat or satin finish.You also don't use oil based products on T1-111 as it will cause delaminating when it attacks the glues in the plywood. would have honestly suggested that any thinned oil based or shellac primer or paint would work wonderously on T1-11 as a 1st, 2nd, or 3rd base coat.