Revision history [back]

There could be several reasons for this issue:

1. The variable scope is incorrect: The variable may not be defined in the correct scope or namespace, causing it to not be recognized by the constructor.

2. The variable name conflicts with another identifier: If the variable name is already used as a class member or another identifier, it may cause naming conflicts and prevent it from being recognized.

3. The syntax is incorrect: If the syntax used to initialize the variable with {} is incorrect, it may cause the compiler to not recognize the variable.

4. A missing header or library: If the variable type is not recognized by the compiler due to a missing header or library, it may cause the variable to not be recognized by the constructor.

To resolve this issue, check the variable definition and syntax, make sure the variable name does not conflict with other identifiers, and ensure that all necessary headers and libraries are included.