When a variable with array type decays to a pointer, its bounds are lost.
If a design requires arrays of different lengths, then a class should be used to encapsulate the array objects and so ensure that the size is
maintained. Note that in C++20, the class std::span is designed for this purpose, and you can find implementation of span
that works with earlier versions of the standard.
Noncompliant code example
void f1( int p[ 10 ] ); // Non-compliant, function called with arguments of array type
void f2( int *p ); // Non-compliant, function is called with arguments of array type
void functionWorkingOnSingleInt(int * p); // Non-compliant, function is called with arguments of array type
void b ()
{
int a[ 10 ];
f1( a ); // The size is lost
f2( a ); // The size is lost
functionWorkingOnSingleInt( a ); // Not clear that the function acts on only one element
}
Compliant solution
void f3( int ( &p )[ 10 ] ); // Compliant
void f4(span<int> s); // Compliant
void functionWorkingOnSingleInt(int * p); // Compliant
void b ()
{
int a[ 10 ];
f3( a ); // size preserved.
f4( a ); // size captured by the span class
functionWorkingOnSingleInt( &a[0] ); // explicit about what happens
}
