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ISO/IEC 9899:2011 Section 6.10.3, "Macro replacement," Section section 6.10.3.2, "The # operator," Section section 6.10.3.3, "The ## operator," Section section 6.10.3.4, "Rescanning and further replacement," and Section section 6.10.8, "Predefined macro names"
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[FSF 2005] Section 3.4, "Stringification," and Section section 3.5, "Concatenation"
[Saks 2008]
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