Fixing LGTM alerts

[hugbug]

This PR is to test LGTM integration. See #604.

[hugbug]

This pull request fixes 52 alerts when merging 017bf3d into 6bf097f - view on LGTM.com

fixed alerts:

• 25 for Unused variable, import, function or class
• 6 for Expression has no effect
• 5 for Superfluous trailing arguments
• 5 for Duplicate character in character class
• 3 for Comparison result is always the same
• 2 for Declaration hides parameter
• 1 for Useless assignment to local variable
• 1 for Inconsistent definition of copy constructor and assignment ('Rule of Two')
• 1 for Wrong type of arguments to formatting function
• 1 for Virtual call from constructor or destructor
• 1 for Conflicting HTML element attributes
• 1 for Ambiguous HTML id attribute

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Comment posted by LGTM.com