Compiling 3.6.0 with GCC > 7, array vs std::array #590 is back

[niklas88]

As a user I can't reopen an issue and I fear commenting on it might get lost.
Anyway as of the 3.6.0 release #590 is back from the dead.
My guess is that the fix of adding parenthesis was removed by some code formatter
here is the problematic line in the current version:

https://github.com/nlohmann/json/blob/release/3.6.0/include/nlohmann/json.hpp#L5731

Also this problem still appears with GCC 8.2.1

[nlohmann]

Thanks for reporting! I am using GCC 7 and 8 in the CI, but did not catch this issue. Strange... Anyway, could you please check whether the issue is fixed in c790b9f?

[niklas88]

Closing as the original issue has been reopened

[nlohmann]

Let's have the regression here.

[niklas88]

Ah, I'm too fast. Yes that patch should fix it as locally adding the parenthesis does

[nlohmann]

---

🔖 Release item

This issue/PR will be part of the next release of the library. This template helps preparing the release notes.

Type

• ✨ New Feature
• 🐛 Bug Fix
• ⚡️ Improvement
• 🔨 Further Change
• 🔥 Deprecated function

Description

• Fixed regression of compiling with gcc 7 -> error on bool operator < #590 which could lead to compilation errors with GCC 7 and GCC 8. Compiling 3.6.0 with GCC > 7, array vs std::array #590 is back #1530

---

[niklas88]

@nlohmann I just found out that the same code in the single_include/nlohmann/json.hpp still has this problem

[nlohmann]

I changed both files. What is the exact error message?

[niklas88]

The parenthesis are wrong it needs to be return (*lhs.m_value.array) < (*rhs.m_value.array); I guess I didn't look close enough in the commit

[nlohmann]

Could you try again with b33093d?

[niklas88]

I've tested with the single include from b33093d and can confirm that it now compiles and works. I'm sorry for getting it wrong last time I think I just assumed that it was the same parenthesis as in 1a9d766 where I looked up the fix.

[nlohmann]

No worries - it was me who got this regression slipped in. Thanks for your help!