compile_flags.txt

-std=c++20

main.cpp

#include "main.hpp"

// all good
static constexpr Container ct1 = Container();

// clangd complaints about three false positives:
// - [invalid_consteval_call] Line 4: call to consteval function 'Container<Value, Value>::Container' is not a constant expression
// - [constexpr_var_requires_const_init] Line 4: constexpr variable 'ct2' must be initialized by a constant expression
// - [invalid_consteval_call] Line 1: in included file: call to consteval function 'Value::raw' is not a constant expression
static constexpr Container ct2 = Container(Value(1), Value(2));

int main() {
  return 0;
}

main.hpp

#pragma once

#include <cstddef>
#include <cstdint>
#include <utility>

class Value final {
 private:
  uint64_t raw_;

 public:
  consteval explicit Value(uint64_t value) : raw_(value * 2){};

  [[nodiscard]] consteval uint64_t raw() const {
	return raw_;
  }
};

template <class... Values>
class Container {
 public:
  consteval explicit Container(Values&&... values) : next_entry_(0), entries_() {
	(Push(std::forward<Values>(values)), ...);
  };

 private:
  static constexpr size_t kEntryCount = sizeof...(Values);

  size_t next_entry_;
  uint64_t entries_[kEntryCount];

  consteval Container& Push(Value value) {
	entries_[next_entry_++] = value.raw();
	return *this;
  }
};

zzz-clangd.log

I[16:21:22.573] clangd version 13.0.0 (https://github.com/llvm/llvm-project d7b669b3a30345cfcdb2fde2af6f48aa4b94845d)
I[16:21:22.573] Features: linux+grpc
I[16:21:22.573] PID: 489995
I[16:21:22.573] Working directory: /home/ppmathis/Development/cpp-playground
I[16:21:22.573] argv[0]: /home/ppmathis/Downloads/clangd/clangd_13.0.0/bin/clangd
I[16:21:22.573] argv[1]: --check=main.cpp
I[16:21:22.573] argv[2]: --log=verbose
V[16:21:22.573] User config file is /home/ppmathis/.config/clangd/config.yaml
I[16:21:22.573] Entering check mode (no LSP server)
I[16:21:22.573] Testing on source file /home/ppmathis/Development/cpp-playground/main.cpp
I[16:21:22.573] Loading compilation database...
I[16:21:22.574] Loaded compilation database from /home/ppmathis/Development/cpp-playground/compile_flags.txt
V[16:21:22.575] Broadcasting compilation database from /home/ppmathis/Development/cpp-playground
I[16:21:22.576] Compile command from CDB is: /home/ppmathis/Downloads/clangd/clangd_13.0.0/bin/clang-tool -std=c++20 -resource-dir=/home/ppmathis/Downloads/clangd/clangd_13.0.0/lib/clang/13.0.0 -- /home/ppmathis/Development/cpp-playground/main.cpp
I[16:21:22.576] Parsing command...
I[16:21:22.579] internal (cc1) args are: -cc1 -triple x86_64-unknown-linux-gnu -fsyntax-only -disable-free -disable-llvm-verifier -discard-value-names -main-file-name main.cpp -mrelocation-model static -mframe-pointer=all -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/home/ppmathis/Development/cpp-playground -resource-dir /home/ppmathis/Downloads/clangd/clangd_13.0.0/lib/clang/13.0.0 -internal-isystem /usr/lib/gcc/x86_64-redhat-linux/11/../../../../include/c++/11 -internal-isystem /usr/lib/gcc/x86_64-redhat-linux/11/../../../../include/c++/11/x86_64-redhat-linux -internal-isystem /usr/lib/gcc/x86_64-redhat-linux/11/../../../../include/c++/11/backward -internal-isystem /home/ppmathis/Downloads/clangd/clangd_13.0.0/lib/clang/13.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-redhat-linux/11/../../../../x86_64-redhat-linux/include -internal-externc-isystem /include -internal-externc-isystem /usr/include -std=c++20 -fdeprecated-macro -fdebug-compilation-dir=/home/ppmathis/Development/cpp-playground -ferror-limit 19 -fgnuc-version=4.2.1 -fno-implicit-modules -fcxx-exceptions -fexceptions -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -x c++ /home/ppmathis/Development/cpp-playground/main.cpp
I[16:21:22.580] Building preamble...
I[16:21:22.659] Indexing headers...
V[16:21:22.670] indexed preamble AST for /home/ppmathis/Development/cpp-playground/main.cpp version null:
  symbol slab: 2191 symbols, 582160 bytes
  ref slab: 0 symbols, 0 refs, 128 bytes
  relations slab: 234 relations, 4376 bytes
V[16:21:22.680] Build dynamic index for header symbols with estimated memory usage of 2092580 bytes
V[16:21:22.681] Built preamble of size 1010908 for file /home/ppmathis/Development/cpp-playground/main.cpp version null
I[16:21:22.681] Building AST...
E[16:21:22.686] [invalid_consteval_call] Line 4: call to consteval function 'Container<Value, Value>::Container' is not a constant expression
E[16:21:22.686] [constexpr_var_requires_const_init] Line 4: constexpr variable 'ct2' must be initialized by a constant expression
E[16:21:22.686] [invalid_consteval_call] Line 1: in included file: call to consteval function 'Value::raw' is not a constant expression
I[16:21:22.686] Indexing AST...
V[16:21:22.686] indexed file AST for /home/ppmathis/Development/cpp-playground/main.cpp version null:
  symbol slab: 3 symbols, 4912 bytes
  ref slab: 7 symbols, 13 refs, 4416 bytes
  relations slab: 0 relations, 24 bytes
V[16:21:22.686] Build dynamic index for main-file symbols with estimated memory usage of 13000 bytes
I[16:21:22.686] Testing features at each token (may be slow in large files)
V[16:21:22.686]   0:0 #
V[16:21:22.686]     definition: 1
V[16:21:22.686]     hover: false
V[16:21:22.686]   0:1 include
V[16:21:22.686]     definition: 1
V[16:21:22.686]     hover: false
V[16:21:22.686]   0:9 "main.hpp"
V[16:21:22.686]     definition: 1
V[16:21:22.686]     hover: false
V[16:21:22.686]   2:0 static
V[16:21:22.686]     definition: 1
V[16:21:22.686]     hover: true
V[16:21:22.686]   2:7 constexpr
V[16:21:22.687]     definition: 1
V[16:21:22.687]     hover: true
V[16:21:22.687]   2:17 Container
V[16:21:22.687]     definition: 1
V[16:21:22.687]     hover: true
V[16:21:22.687]   2:27 ct1
V[16:21:22.687]     definition: 1
V[16:21:22.687]     hover: true
V[16:21:22.687]   2:31 =
V[16:21:22.687]     definition: 1
V[16:21:22.687]     hover: true
V[16:21:22.687]   2:33 Container
V[16:21:22.687]     definition: 1
V[16:21:22.688]     hover: true
V[16:21:22.688]   2:42 (
V[16:21:22.688]     definition: 1
V[16:21:22.688]     hover: true
V[16:21:22.688]   2:43 )
V[16:21:22.688]     definition: 1
V[16:21:22.688]     hover: true
V[16:21:22.688]   2:44 ;
V[16:21:22.688]     definition: 1
V[16:21:22.688]     hover: true
V[16:21:22.688]   3:0 static
V[16:21:22.688]     definition: 1
V[16:21:22.689]     hover: true
V[16:21:22.689]   3:7 constexpr
V[16:21:22.689]     definition: 1
V[16:21:22.689]     hover: true
V[16:21:22.689]   3:17 Container
V[16:21:22.689]     definition: 1
V[16:21:22.689]     hover: true
V[16:21:22.689]   3:27 ct2
V[16:21:22.689]     definition: 1
V[16:21:22.689]     hover: true
V[16:21:22.689]   3:31 =
V[16:21:22.689]     definition: 1
V[16:21:22.690]     hover: true
V[16:21:22.690]   3:33 Container
V[16:21:22.690]     definition: 1
V[16:21:22.690]     hover: true
V[16:21:22.690]   3:42 (
V[16:21:22.690]     definition: 1
V[16:21:22.690]     hover: true
V[16:21:22.690]   3:43 Value
V[16:21:22.690]     definition: 1
V[16:21:22.690]     hover: true
V[16:21:22.691]   3:48 (
V[16:21:22.691]     definition: 1
V[16:21:22.691]     hover: true
V[16:21:22.691]   3:49 1
V[16:21:22.691]     definition: 1
V[16:21:22.691]     hover: false
V[16:21:22.691]   3:50 )
V[16:21:22.691]     definition: 1
V[16:21:22.691]     hover: true
V[16:21:22.691]   3:51 ,
V[16:21:22.691]     definition: 1
V[16:21:22.691]     hover: true
V[16:21:22.691]   3:53 Value
V[16:21:22.691]     definition: 1
V[16:21:22.692]     hover: true
V[16:21:22.692]   3:58 (
V[16:21:22.692]     definition: 1
V[16:21:22.692]     hover: true
V[16:21:22.692]   3:59 2
V[16:21:22.692]     definition: 1
V[16:21:22.692]     hover: false
V[16:21:22.692]   3:60 )
V[16:21:22.692]     definition: 1
V[16:21:22.692]     hover: true
V[16:21:22.692]   3:61 )
V[16:21:22.692]     definition: 1
V[16:21:22.692]     hover: true
V[16:21:22.692]   3:62 ;
V[16:21:22.693]     definition: 1
V[16:21:22.693]     hover: true
V[16:21:22.693]   5:0 int
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
V[16:21:22.693]   5:4 main
V[16:21:22.693]     definition: 1
V[16:21:22.693]     hover: true
V[16:21:22.693]   5:8 (
V[16:21:22.693]     definition: 1
V[16:21:22.693]     hover: false
V[16:21:22.693]   5:9 )
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
V[16:21:22.693]   5:11 {
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
V[16:21:22.693]   6:2 return
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
V[16:21:22.693]   6:9 0
V[16:21:22.693]     tweak: ExtractVariable
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
V[16:21:22.693]   6:10 ;
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
V[16:21:22.693]   7:0 }
V[16:21:22.693]     definition: 0
V[16:21:22.693]     hover: false
I[16:21:22.693] All checks completed, 3 errors