`LoggerFile( const fs::path &filePath = fs::path(), bool appendToExisting = true );`

- `filePath` defines the target logfile. For example, `/tmp/cinder.log`. If this parameter is left blank, LoggerFile will target a file named `cinder.log` that will sit next to the application binary.
- `appendToExisting` configures file appending. This parameter defaults to `true`.

`LoggerFileRotating( const fs::path &folder, const std::string &formatStr, bool appendToExisting = true );`

- `folder` defines the root folder that will contain the logfile. If a blank string is provided, the folder will default to the folder that contains the application binary.
- `formatStr` is the string that will be evaluated by strftime and turned into the logfile name. For example, the string `cinder.%Y.%m.%d.log` could evaluate to `cinder.2015.08.28.log`. Note that, since the log name is only re-evaluated once daily, using a format that includes minutes or seconds may not produce the results you're expecting. If a blank format string is provided, an assertion will be thrown.
- `appendToExisting` configures file appending. This parameter defaults to `true`.