ToolHandle: add EnableTool tagged bool to control retrieval

The syntax of

  ToolHandle<IMyTool> m_tool;
  bool m_useToolFlag;
...
  ATH_CHECK( m_tool.retrieve( DisableTool{ !m_useToolFlag } ));

is a little confusing. This MR adds another TaggedBool to make it a little clearer:

   ATH_CHECK( m_tool.retrieve( EnableTool{ m_useToolFlag } ));

what are people's thoughts on DisableTool / EnableTool vs. DisableToolIf / EnableToolIf

• [2018-01-31 19:08] Validation started with lhcb-gaudi-merge#402
• [2018-02-01 00:04] Validation started with lhcb-gaudi-head-py3#51
• [2018-02-01 00:07] Validation started with lhcb-tdr-test#44
• [2018-02-01 00:11] Validation started with lhcb-gaudi-head#1742
• [2018-02-01 10:01] Validation started with lhcb-gaudi-head#1743
• [2018-02-01 11:37] Validation started with lhcb-tdr-test#45
• [2018-02-02 00:06] Validation started with lhcb-gaudi-head-py3#52
• [2018-02-02 00:06] Validation started with lhcb-tdr-test#46
• [2018-02-02 00:07] Validation started with lhcb-gaudi-head#1744
• [2018-02-02 11:52] Validation started with lhcb-upgrade-hackathon#1
• [2018-02-02 11:57] Validation started with lhcb-upgrade-hackathon#2
• [2018-02-02 15:45] Validation started with lhcb-upgrade-hackathon#3
• [2018-02-02 15:58] Validation started with lhcb-upgrade-hackathon#4
• [2018-02-02 17:32] Validation started with lhcb-upgrade-hackathon#5
• [2018-02-02 21:03] Validation started with lhcb-upgrade-hackathon#6
• [2018-02-03 00:04] Validation started with lhcb-gaudi-head-py3#53
• [2018-02-03 00:06] Validation started with lhcb-tdr-test#47
• [2018-02-03 00:06] Validation started with lhcb-upgrade-hackathon#7
• [2018-02-03 00:08] Validation started with lhcb-gaudi-head#1745
• [2018-02-04 00:04] Validation started with lhcb-gaudi-head-py3#54
• [2018-02-04 00:05] Validation started with lhcb-upgrade-hackathon#8
• [2018-02-04 00:06] Validation started with lhcb-tdr-test#48
• [2018-02-04 00:08] Validation started with lhcb-gaudi-head#1746
• [2018-02-05 00:05] Validation started with lhcb-gaudi-head-py3#55
• [2018-02-05 00:06] Validation started with lhcb-upgrade-hackathon#9
• [2018-02-05 00:09] Validation started with lhcb-tdr-test#49
• [2018-02-05 00:10] Validation started with lhcb-gaudi-head#1747
• [2018-02-05 09:40] Validation started with lhcb-upgrade-hackathon#10
• [2018-02-05 09:42] Validation started with lhcb-tdr-test#50
• [2018-02-05 09:52] Validation started with lhcb-gaudi-head#1748
• [2018-02-06 00:03] Validation started with lhcb-gaudi-head-py3#56
• [2018-02-06 00:06] Validation started with lhcb-tdr-test#51
• [2018-02-06 00:08] Validation started with lhcb-gaudi-head#1749
• [2018-02-07 00:04] Validation started with lhcb-gaudi-head-py3#57
• [2018-02-07 00:04] Validation started with lhcb-tdr-test#52
• [2018-02-07 00:08] Validation started with lhcb-gaudi-head#1750
• [2018-02-08 00:04] Validation started with lhcb-gaudi-head-py3#58
• [2018-02-08 00:08] Validation started with lhcb-tdr-test#53
• [2018-02-08 00:09] Validation started with lhcb-gaudi-head#1751
• [2018-02-08 13:43] Validation started with lhcb-gaudi-head#1752
• [2018-02-09 00:05] Validation started with lhcb-gaudi-head-py3#59
• [2018-02-09 00:07] Validation started with lhcb-tdr-test#54
• [2018-02-09 00:13] Validation started with lhcb-gaudi-head#1753

changed the description

ping? any comments on the syntax?

mentioned in merge request atlas/Gaudi!164 (merged)

added 1 commit

• 9635c6eb - change UseTool to EnableTool

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changed title from ToolHandle: add UseTool tagged bool to control retrieval to ToolHandle: add EnableTool tagged bool to control retrieval

changed the description

added 1 commit

• a59d33d4 - formatting

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approved this merge request

assigned to @clemenci

changed milestone to %v30r2

added C++ framework label

merged

mentioned in commit e00b4520

mentioned in issue #174