Separating main() for testing
As we've established, the linker enforces the ODR and ensures that all external symbols provide their definitions during the linking process. Another linker-related challenge we might face is elegant and efficient testing of the project.
In an ideal scenario, we should be testing the exact same source code that runs in production. A comprehensive testing pipeline would build the source code, run tests on the resulting binary, and then package and distribute the executable (optionally excluding the tests themselves).
But how can we implement this? Executables typically have a precise execution flow, often involving the reading of command-line arguments. The compiled nature of C++ doesn't readily support pluggable units that can be temporarily injected into the binary just for testing. This suggests that we may need a nuanced approach to tackle this challenge.
Luckily, we can use a linker to help us deal with this in an elegant manner. Consider extracting...
