What are unevaluated contexts in C++?

Question

One example that frequently comes to mind is :

sizeof expression, where it doesn\'t evaluates the expression but determines the size by static type. For

Answer 1

The standard term is an unevaluated operand and you can find it in [expr]

In some contexts, unevaluated operands appear (5.2.8, 5.3.3, 5.3.7, 7.1.6.2). An unevaluated operand is not evaluated. An unevaluated operand is considered a full-expression. [ Note: In an unevaluated operand, a non-static class member may be named (5.1) and naming of objects or functions does not, by itself, require that a definition be provided (3.2). —end note ]

• 5.2.8 covers typeid
• 5.3.3 covers sizeof
• 5.3.7 covers noexcept
• 7.1.6.2 covers simple type specifiers such as auto and decltype and POD types like int, char, double etc.