... you are too slow and QJson API is so ugly.
Now using this wonderful json lib:
https://github.com/nlohmann/json
Results in release mode (QJson tests are not shown but
QJson was even slower than string concat).
PASS : TestQgsJsonUtils::testExportAttributesJson(Use json)
RESULT : TestQgsJsonUtils::testExportAttributesJson():"Use json":
0.0022 msecs per iteration (total: 75, iterations: 32768)
PASS : TestQgsJsonUtils::testExportAttributesJson(Use old string concat)
RESULT : TestQgsJsonUtils::testExportAttributesJson():"Use old string concat":
0.0032 msecs per iteration (total: 54, iterations: 16384)
PASS : TestQgsJsonUtils::testExportFeatureJson(Use json)
RESULT : TestQgsJsonUtils::testExportFeatureJson():"Use json":
0.011 msecs per iteration (total: 96, iterations: 8192)
PASS : TestQgsJsonUtils::testExportFeatureJson(Use old string concat)
RESULT : TestQgsJsonUtils::testExportFeatureJson():"Use old string concat":
0.015 msecs per iteration (total: 64, iterations: 4096)
PASS : TestQgsJsonUtils::testExportGeomToJson(Use json)
RESULT : TestQgsJsonUtils::testExportGeomToJson():"Use json":
0.76 msecs per iteration (total: 98, iterations: 128)
PASS : TestQgsJsonUtils::testExportGeomToJson(Use old string concat)
RESULT : TestQgsJsonUtils::testExportGeomToJson():"Use old string concat":
0.85 msecs per iteration (total: 55, iterations: 64)
PASS : TestQgsJsonUtils::cleanupTestCase()