Ideally, a program should be statically type safe

Reason

Ideally, a program would be completely statically (compile-time) type safe. Unfortunately, that is not possible. Problem areas:

• unions
• casts
• array decay
• range errors
• narrowing conversions

Note

These areas are sources of serious problems (e.g., crashes and security violations). We try to provide alternative techniques.

Enforcement

We can ban, restrain, or detect the individual problem categories separately, as required and feasible for individual programs. Always suggest an alternative. For example:

• unions -- use variant (in C++17)
• casts -- minimize their use; templates can help
• array decay -- use span (from the GSL)
• range errors -- use span
• narrowing conversions -- minimize their use and use narrow or narrow_cast (from the GSL) where they are necessary