Compiler warning: -Wmissing-field-initializers in FIX::DateTime::getTmUtc() (FieldTypes.h) #753

When compiling QuickFIX with compiler warnings enabled (-Wextra / -Wall), GCC/Clang emit a -Wmissing-field-initializers warning in src/C++/FieldTypes.h inside FIX::DateTime::getTmUtc().

The variable result is initialized using tm result = {0};, which triggers compiler warnings for missing initializers for struct tm fields (tm_min, tm_hour, tm_gmtoff, tm_zone, etc.).

Steps to Reproduce

1. Configure QuickFIX with -DCMAKE_CXX_FLAGS="-Wall -Wextra":

   cmake -S . -B build -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_FLAGS="-Wall -Wextra"

2. Build the project:

  cmake --build build

Expected Behavior

The codebase should compile cleanly without -Wmissing-field-initializers warnings on standard C++ compilers.

Actual Behavior

The compiler outputs the following warnings:

src/C++/FieldTypes.h:231:19: warning: missing initializer for member ‘tm::tm_min’ [-Wmissing-field-initializers]
src/C++/FieldTypes.h:231:19: warning: missing initializer for member ‘tm::tm_hour’ [-Wmissing-field-initializers]
src/C++/FieldTypes.h:231:19: warning: missing initializer for member ‘tm::tm_gmtoff’ [-Wmissing-field-initializers]
src/C++/FieldTypes.h:231:19: warning: missing initializer for member ‘tm::tm_zone’ [-Wmissing-field-initializers]

Location

• File: src/C++/FieldTypes.h
• Function: FIX::DateTime::getTmUtc()
• Line 231: tm result = {0};

Proposed Fix

Change tm result = {0}; to tm result = {}; (or tm result{};), which value-initializes all fields of struct tm without triggering -Wmissing-field-initializers.

Environment

• QuickFIX version: latest master
• OS: Linux (Ubuntu x86_64)
• Compiler: GCC 11 / Clang (with C++17)