Why Does My Constructor With No Arguments Cause a Compilation Error?

Clearing the Confusion: Understanding the "Constructor with No Arguments" Syntax

When attempting to initialize an object with a constructor having no arguments, programmers may encounter the enigmatic compile-time error "error: request for member '<>' in '<>', which is of non-class type '<> ()()'". This puzzling message stems from a syntactic ambiguity in C .

Traditionally, in C , constructors with no arguments could be declared in two syntactically equivalent ways:

1. MyClass myObj;
2. MyClass myObj();

However, the language standard dictates that an empty parentheses constructor declaration will always be interpreted as a function declaration, leaving no room for an empty constructor initialization.

In contrast, an empty parentheses initializer is permitted in specific scenarios, such as when initializing a class in a new expression or constructing a value-initialized temporary. Therefore, to resolve the parse error and define an empty constructor, programmers must explicitly exclude the parentheses and write:

MyClass myObj;

This clarification resolves the ambiguity and ensures that the compiler correctly interprets the code as an object definition with an empty initializer, allowing the program to compile successfully.

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