Function with default parameter doesn't get it's prototype in *.h header file.

[obiwan-bartek]

When you write a function with at least one parameter with default value
eg.

void foo(int a, int b = 0)
{
}

it does not gets generated it's prototype in header file, which results in an unreferenced calls in project to that function. When you remove the default parameter

 = 0

the prototype shows in header file as expected.

[NicoHood]

You need to do:

// prototype
void foo(int a, int b = 0);

// Implementation, better place inside a .cpp or marke the prototype above as static inline
void foo(int a, int b)
{

}

[ffissore]

This issue was moved to arduino/arduino-builder#39