error: conversion from 'std::size_t' {aka 'long long unsigned int'} to 'long int' may change value [-Werror=conversion]

[robe]

Seeing this error on winnie's gcc 8.1 64-bit builds. Strk says he is seeing the same errors. This is with cmake 3.15.4. I'm going to up it and see if things improve.

-- GEOS: Build type: Release
-- GEOS: Run-time output: E:/jenkins/geos/branches/build64cmake3.10/bin
-- GEOS: Archives output: E:/jenkins/geos/branches/build64cmake3.10/lib
-- The C compiler identification is GNU 8.1.0
-- The CXX compiler identification is GNU 8.1.0
-- Check for working C compiler: C:/ming64gcc81/mingw64/bin/gcc.exe
-- Check for working C compiler: C:/ming64gcc81/mingw64/bin/gcc.exe -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: C:/ming64gcc81/mingw64/bin/g++.exe
-- Check for working CXX compiler: C:/ming64gcc81/mingw64/bin/g++.exe -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- GEOS: Version 3.10.0dev
-- GEOS: C API Version 1.15.0
-- GEOS: JTS port 1.17.0
-- GEOS: Require C++11
-- GEOS: Function inlining ENABLED
-- GEOS: Developer mode ENABLED
-- GEOS: Configured 'dist' target
-- GEOS: Configured 'distcheck' target
-- Configuring done
-- Generating done

[ 98%] [32mBuilding CXX object util/geosop/CMakeFiles/geosop.dir/GeosOp.cpp.obj[0m
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp: In function 'bool isWKTLiteral(std::__cxx11::string)':
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp:171:32: error: conversion from 'std::__iterator_traits<__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >, void>::difference_type' {aka 'long long int'} to 'long int' may change value [-Werror=conversion]
     long numLParen = std::count(s.begin(), s.end(), '(');
                      ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp: In member function 'void GeosOp::executeUnary(GeomFunction*)':
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp:355:47: error: conversion from 'std::size_t' {aka 'long long unsigned int'} to 'long int' may change value [-Werror=conversion]
         vertexCount += geomA[i]->getNumPoints();
                                               ^
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp: In member function 'void GeosOp::executeBinary(GeomFunction*)':
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp:366:52: error: conversion from 'std::size_t' {aka 'long long unsigned int'} to 'long int' may change value [-Werror=conversion]
             vertexCount += geomA[ia]->getNumPoints();
                                                    ^
E:/jenkins/geos/branches/3.10cmake/util/geosop/GeosOp.cpp:367:52: error: conversion from 'std::size_t' {aka 'long long unsigned int'} to 'long int' may change value [-Werror=conversion]
             vertexCount += geomB[ib]->getNumPoints();
                                                    ^
At global scope:
cc1plus.exe: error: unrecognized command line option '-Wno-unknown-warning-option' [-Werror]
cc1plus.exe: all warnings being treated as errors
make[2]: *** [util/geosop/CMakeFiles/geosop.dir/build.make:64: util/geosop/CMakeFiles/geosop.dir/GeosOp.cpp.obj] Error 1
make[1]: *** [CMakeFiles/Makefile2:1962: util/geosop/CMakeFiles/geosop.dir/all] Error 2
make: *** [Makefile:163: all] Error 2

I'm seeing a bunch of errors on 32-bit but will look at those closer