inline function in qdatetime.h

In qt-x11-opensource-src-4.2.2/src/corelib/tools/qdatetime.h, line 40 has

Code:

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bool isNull() const { return jd == 0; }

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and line 101 has

Code:

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inline int toJulianDay() const { return jd; }

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As I understand it, all functions defined inside a class definition are automatically inline. Then why does line 101 have the inline keyword while line 40 does not? Is there any special meaning?

my guess is that the two functions were not written by the same person or/and at the same time.
There is no difference between the two declerations from the compilers perspective.