This change fixes the following warnings:

```
    -Wc++98-compat-extra-semi
    -Wc++98-compat-local-type-template-args
    -Wc++98-compat-pedantic
    -Wc++98-compat
    -Wcomma
    -Wdeprecated-copy-dtor
    -Wexit-time-destructors
    -Wextra-semi-stmt
    -Wextra-semi
    -Wfloat-conversion
    -Wfloat-equal
    -Wformat-nonliteral
    -Wglobal-constructors
    -Winconsistent-missing-destructor-override
    -Wnon-virtual-dtor
    -Wold-style-cast
    -Wpadded
    -Wreturn-std-move-in-c++11
    -Wshadow-field-in-constructor
    -Wshadow-uncaptured-local
    -Wshift-sign-overflow
    -Wsign-conversion
    -Wundef
    -Wunreachable-code-return
    -Wused-but-marked-unused
    -Wweak-vtables
    -Wzero-as-null-pointer-constant
```